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PEER REVIEW: Mt. Umunhum Radar Tower (Building 102) Historical Evaluation JRP Historical Consulting, LLC 2850 Spafford Street Davis, CA 95618 December 17, 2015 PEER REVIEW Mt. Umunhum Radar Tower (Building 102) Historical Evaluation Prepared for: Robert Salisbury, Planner III County of Santa Clara Planning Office 70 W. Hedding Street, East Wing, 7th Floor San Jose, CA 95110 Prepared by: Heather Norby JRP Historical Consulting, LLC 2850 Spafford Street Davis, CA 95618 December 17, 2015 JRP Historical Consulting, LLC 2015 TABLE OF CONTENTS 1. Introduction ................................................................................................................................. 1 2. Brief Historic Context of Mt. Umunhum Radar Tower (Building 102) ............................................ 2 3. Summary of Previous Studies ....................................................................................................... 3 3.1. Page & Turnbull Analysis – 2011 ................................................................................................... 3 3.2. Archives & Architecture Analysis – 2014 ...................................................................................... 6 4. Analysis of Significance and Integrity of Mt. Umunhum Radar Tower (Building 102) ..................... 8 4.1. Essential Physical Features of Mt. Umunhum Radar Tower (Building 102)................................ 11 4.2. Integrity of Mt. Umunhum Radar Tower (Building 102) ............................................................. 12 5. Conclusion .................................................................................................................................. 15 6. Preparers’ Qualifications ............................................................................................................ 16 Appendix A: Page & Turnbull 2011 Report Appendix B: Page & Turnbull 2011 Addendum Appendix C: Archives & Architecture 2014 Report PEER REVIEW – MT UMUNHUM RADAR TOWER, BUILDING 102 JRP Historical Consulting, LLC 1. 2015 Introduction Santa Clara County has contracted with JRP Historical Consulting, LLC (JRP) to review two existing historical studies that came to differing conclusions about the eligibility of the Mt. Umunhum Radar Tower (Building 102), located approximately ten miles south of downtown San Jose, for listing in the National Register of Historic Places (NRHP), the California Register of Historical Resources (CRHR), and the Santa Clara County Heritage Resource Inventory, and determine whether or not Building 102 meets any of the significance criteria and retains sufficient historic integrity for listing in any of the registers. The Mt. Umunhum Radar Tower (Building 102), built in 1959‐1961 and made operational in 1962, was part of the former Almaden Air Force Station (Almaden AFS), a military complex that operated at the top of Mt. Umunhum from 1958 through 1980. Mid‐Peninsula Regional Open Space District (Mid‐Pen) acquired the decommissioned station in 1986 and began demolishing the remnant buildings in 2013. The Mt. Umunhum radar tower building is the only remaining building from Almaden AFS. In preparation for demolition of the buildings at the former Almaden AFS, Mid‐Pen hired Page & Turnbull to conduct an historic evaluation of Almaden AFS, which concluded in 2011 that none of the buildings were eligible for listing in the NRHP, CRHR, or the local Santa Clara County Heritage Resource Inventory. With regard to Mt. Umunhum Radar Tower (Building 102), Page & Turnbull concluded that it met NRHP Criterion A / CRHR Criterion 1 and NRHP Criterion C / CRHR Criterion 3 for significance, but that it lacked integrity to convey that significance and therefore is not eligible for listing in either register. In 2014, a local advocacy group hired another firm, Archives & Architecture, LLC, to evaluate Building 102, and that report concluded that the tower is historically significant, retains integrity, and should be placed on the Santa Clara County Heritage Resource Inventory. The Archives and Architecture report did not apply NRHP or CRHR criteria to Building 102.1 In addition to reviewing the previous evaluation studies of the former Almaden AFS site, JRP Staff Historian Heather Norby performed a site visit to Mt. Umunhum on November 24, 2015, accompanied by Meredith Manning of Mid‐Pen and Rob Salisbury of the Santa Clara County Planning Office. Ms. Norby recorded the Mt. Umunhum Radar Tower (Building 102) with notes and digital photographs of the building and the surrounding setting. 1 Page & Turnbull, Inc., “Historic Resource Study: Former Almaden Air Force Station, Mt. Umunhum and Mt. Thayer, Santa Clara County, CA,” prepared for Mid‐Peninsula Regional Open Space District, updated final March 9, 2011; Archives & Architecture, LLC, “Historical Evaluation: Mount Umunhum Radar Tower, Sierra Azul Open Space Preserve, Santa Clara County, California,” prepared for Santa Clara County Historical Heritage Commission, revised May 14, 2014. PEER REVIEW – MT UMUNHUM RADAR TOWER, BUILDING 102 1 JRP Historical Consulting, LLC 2015 JRP concludes in this report, as elaborated in Section 4 below, that Mt. Umunhum Radar Tower (Building 102) is historically significant, retains historic integrity to convey its significance, and is eligible for listing in the NRHP and CRHR. It also qualifies as a landmark under the Santa Clara County Historic Preservation Ordinance and is recommended to be placed on the Santa Clara County Heritage Resource Inventory. 2. Brief Historic Context of Mt. Umunhum Radar Tower (Building 102) The US Air Force (USAF) established Almaden AFS in 1957 to serve as an early warning radar base to protect northern California’s airspace during the Cold War. Radar facilities were clustered at the highest point of the station atop Mt. Umunhum. The first operational radars at the station were an AN/FPS‐20 search radar and an AN/FPS‐6A height finder constructed in 1957. Another AN/FPS‐6A height finder was installed in 1958, and upgraded in 1963 to an AN/FPS‐90. In 1962 an AN/MPS‐14 was constructed to be mobile. The original radar at the site, the AN/FPS‐20, was housed in a dome‐shaped structure, but it was replaced by the massive AN/FPS‐24 that was mounted atop Building 102, the subject of this report. Mt. Umunhum Radar Tower (Building 102) is a massive concrete structure that was built from 1959‐ 1961 to support the new radar, and it also housed a height finder shop (Photograph 1).2 The AN/FPS‐24 search radar that went online in 1962 atop the Mt. Umunhum Radar Tower (Building 102) was the second of twelve production models built nationwide between 1958 and 1962, and one of a series of radars in the Semi‐Automatic Ground Environment (SAGE) system that allowed the military to analyze data simultaneously from many radar stations. The AN/FPS‐24 at Almaden AFS had a 250‐mile range which was farther than the 200‐mile range of some of the other models. During its years of service at Almaden AFS, 1962‐1980, the radar was rarely updated and it does not appear as though any substantive changes were made to Mt. Umunhum Radar Tower (Building 102) upon which the radar sail was mounted. The radar sail was removed from the building in 1980.3 2 3 Page & Turnbull, “Historic Resource Study,” 21‐28. Page & Turnbull, “Historic Resource Study,” 28. PEER REVIEW – MT UMUNHUM RADAR TOWER, BUILDING 102 2 JRP Historical Consulting, LLC 2015 Photograph 1: 1962 photograph of Mt. Umunhum Radar Tower (Building 102) excerpted from Archives & Architecture 2014 report. Note radar AN/FPS‐24 radar sail mounted on top.4 3. Summary of Previous Studies 3.1. Page & Turnbull Analysis – 2011 Page & Turnbull concluded that Mt. Umunhum Radar Tower (Building 102) is historically significant, but that it lacks integrity to convey its significance. The evaluation of Building 102 states: Significant to former Almaden AFS under Criterion A/1 (Events) as the most prominent and directly‐related example of radar operation at the site, and Criterion C/3 (Architecture/Design) as the only concrete radar tower at the site which was built for 4 Archives & Architecture, “Historical Evaluation,” 9. PEER REVIEW – MT UMUNHUM RADAR TOWER, BUILDING 102 3 JRP Historical Consulting, LLC 2015 one of the most high‐powered antennas in California. However, it is not individually eligible for the National Register or California Register due to lack of integrity.5 The report also notes that Mt. Umunhum Radar Tower (Building 102) was one of three buildings clustered at the top of Mt. Umunhum that “best represent the historic function of the former Almaden Air Force Station.”6 The other two – both since demolished – were the steel tower for another radar, and the training building. In particular, Mt. Umunhum Radar Tower (Building 102) is called out as the “most impressive structure at the site.”7 The report included these recommendations about future uses of the building: If it were to be retained, it could potentially be used as an interpretive center that discusses the historic use of the former Almaden AFS. Interpretive signage about the site, the building, and the AN/FPS‐24 that was once located there could be installed…Conversely, the building could be fully sealed, the interior unused by visitors. In this case, the building would continue to serve as a local icon and interpretive materials could be placed on the exterior.8 Page & Turnbull concluded that Mt. Umunhum Radar Tower (Building 102) did not retain historic integrity to convey its significance. Regarding the lack of integrity, the report states that Building 102: Lacks integrity of materials, workmanship, and association, largely because the radar unit on the roof and the other technical machinery to operate the radar has been removed. The removal of the radar and equipment prevents the building from directly conveying a connection to its historic function and design.9 Page & Turnbull’s integrity analysis of Mt. Umunhum Radar Tower (Building 102) rests upon methodology that considers workmanship and association the most valuable aspects of integrity in the evaluation of resources at Alamden AFS. Regarding the methodology applied to integrity, the report states: For the forty‐seven resources reviewed at the former Almaden AFS, the aspects of integrity deemed to be of the highest value in the evaluation process were workmanship and association. These two aspects allowed for latitude in the evaluation of the other aspects of integrity, which may have been significantly altered. As defined previously, workmanship is the physical evidence of the crafts of a particular culture or 5 Page & Turnbull, “Historic Resource Study,” 55. Page & Turnbull, “Historic Resource Study,” 85. 7 Page & Turnbull, “Historic Resource Study,” 86. 8 Page & Turnbull, “Historic Resource Study,” 86. 9 Page & Turnbull, “Historic Resource Study,” 55. 6 PEER REVIEW – MT UMUNHUM RADAR TOWER, BUILDING 102 4 JRP Historical Consulting, LLC 2015 people during any given period in history or prehistory, and association is the direct link between an important historic event or person and a historic property. Although workmanship is often associated with traditional crafts and construction techniques, it can be adapted to suit the evaluation of scientific and technical resources. Examples of workmanship for these types of facilities include the presence of specialized infrastructure, large‐scale cranes, vacuum spheres, and cable trays. These resources are often vital in the facility’s operational mission, and serve as the physical evidence of work conducted in a particular time and place. In many cases, equipment and technological resources function as the primary historic elements within technical facilities, and the building housing them is often treated as a shell adapted to these resources. While the character of the equipment may change or evolve over time, the function of this equipment or technology remains constant despite the changes in appearance or design. Therefore, in evaluating the workmanship of radar facilities, significant equipment that played a role in the history of Cold War military programs must be noted in the context statement and integrity evaluation. Although the structure or building may physically change and evolve over time, if the significant equipment and technological resources used in that military function still exist, even if altered, then a resource may retain integrity of workmanship. In a scientific or highly technical facility, integrity of workmanship is defined as the constant evolution of equipment and technology constructed for a specific goal. This technology often results in significant events or associations that are embodied within a place. The National Park Service defines this connection as the integrity of association – the direct link between an important historic event or person and an historic property. The National Park Service recognizes integrity of association as being subjective, and often, ephemeral in nature. The integrity of association of a scientific or highly technical facility is vital to convey its significance because some identifiable link to the significant event or person is essential. Integrity of association is not solely defined by its aesthetic attributes, which are identified as the integrity of feeling. Technical facilities often lack this integrity of feeling, due to the evolution of the physical characteristics, which would have originally defined a building, structure, or object. The integrity of association is more closely tied to the place. Therefore, integrity of association is required in order to convey a scientific or highly technical facility’s connection to a past discovery or achievement.10 Page & Turnbull prepared an addendum report in August 2011 to address the potential for any of the buildings at Almaden AFS to have local significance that could render them eligible for 10 Page & Turnbull, “Historic Resource Study,” 13‐14. PEER REVIEW – MT UMUNHUM RADAR TOWER, BUILDING 102 5 JRP Historical Consulting, LLC 2015 listing in the NRHP or CRHR at the local level, or eligible for the Santa Clara County Heritage Resource Inventory. The addendum report examined Almaden AFS within the context of other Cold War‐era military installations in Santa Clara County. It concludes that within the context of Santa Clara County Cold War‐era military presence, the former Onizuka AFS, just outside of Sunnyvale, contains the most historically significant military buildings in the county. The report acknowledges that when placed within Santa Clara County’s Cold War military context, Almaden AFS may have been considered locally significant if it retained integrity. Page & Turnbull’s addendum report specifically addressed Mt. Umunhum Radar Tower (Building 102), concluding: The buildings at the former Almaden Air Force Station, though constructed in the early years of Cold War‐era defense advancement, do not retain sufficient materials, workmanship, feeling or association to maintain their historic integrity. This includes Building 102 (the Radar Tower), which, though a large and visually identifiable structure from the base of the mountain, does not retain the radar sail or interior mechanics that associate it with its former defense function.11 In summary, Page & Turnbull concluded that Mt. Umunhum Radar Tower (Building 102) is significant under NRHP Criteria A and C / CRHR Criteria 1 and 3, but that the loss of the radar sail and interior equipment is a fatal loss to its integrity that prevents it from conveying its historic significance. 3.2. Archives & Architecture Analysis – 2014 The analysis prepared in 2014 by Archives & Architecture evaluated Mt. Umunhum Radar Tower (Building 102) for eligibility for designation as a County of Santa Clara Landmark. The study did not evaluate the building or the site using NRHP or CRHP criteria. The stated intent of the Santa Clara County Historic Preservation Ordinance is “for the preservation, protection, enhancement, and perpetuation of resources of architectural, historical, and cultural merit within Santa Clara County and to benefit the social and cultural enrichment, and general welfare of the people” (Sec. C17‐1.). The ordinance lays out the following criteria whereby the Board of Supervisors may designate historic resources as landmarks. A. Fifty years or older. If less than 50 years old, sufficient time must have passed to obtain a scholarly perspective on the events or individuals associated with the historic resource and/or the historic resource is a distinctive or important example of its type or style; and 11 Page & Turnbull, Inc., “Historic Resource Study: Former Almaden Air Force Station, Mt. Umunhum and Mt. Thayer, Santa Clara County, CA,” prepared for Mid‐Peninsula Regional Open Space District, addendum August 4, 2011; 8. PEER REVIEW – MT UMUNHUM RADAR TOWER, BUILDING 102 6 JRP Historical Consulting, LLC 2015 B. Retains historic integrity. If a historic resource was moved to prevent demolition at its former location, it may still be considered eligible if the new location is compatible with the original character of the property; and C. Meets one or more of the following criteria of significance: 1. Associated with events that have made a significant contribution to the broad patterns of local or regional history, or the cultural heritage of California or the United States; 2. Associated with the lives of persons important to local, California or national history; 3. Embodies the distinctive characteristics of a type, period, region, or method of construction, or represents the work of a master or possesses high artistic values; or 4. Yielded or has the potential to yield information important to the pre‐history or history of the local area, California, or the nation. These criteria generally conform to the criteria for eligibility for listing in the NRHP or CRHR. The significance criteria for evaluation designated by the ordinance mirror the NRHP and CRHR criteria with one notable exception. The ordinance adds “or the cultural heritage of California or the United States” under significance Criterion 1. The NRHP and CRHR significance criteria do not contain any references to “cultural heritage,” a phrase whose meaning is very broad and offers expansive latitude for interpretation. Archives & Architecture applied the Santa Clara County Historic Preservation Ordinance to Mt. Umunhum Radar Tower (Building 102) and, like Page & Turnbull, reached the conclusion that it is historically significant. The report argues that under Criterion 1 of the ordinance: The Mount Umunhum Radar Tower is individually significant at the local level within the former Almaden Air Force Station under Criterion 1 as a prominent example of radar operation at the site and within the Santa Clara County itself. Though not the first or only radar erected at the Almaden Air Force Station, it best represents the overall mission and purpose of Almaden AFS, and has served as a visual symbol of an important era in county history to the county due to its prominent perch above the valley. Of all the remaining artifacts of the Cold War era from 1959 to 1980, the Radar Tower at Mount Umunhum remains the most visual and memorable icon, easily recognizable to the entire population of Santa Clara County. It is of historic significance within the county due to its prominent, distinctive image, its important associations, and the expansive understanding of what it represents to the local population. The property meets Criterion 1 under the County’s ordinance for landmark designation.12 12 Archives & Architecture, “Historical Evaluation,” 19. PEER REVIEW – MT UMUNHUM RADAR TOWER, BUILDING 102 7 JRP Historical Consulting, LLC 2015 And under Criterion 3 of the ordinance: The Mount Umunhum Radar Tower is individually significant locally under Criterion 3 as a unique concrete radar tower in Santa Clara County, that once supported the highest‐powered radar antenna at the now decommissioned Almaden Air Force Station site. The Radar Tower is a distinctive architectural specimen, both for its unique construction as a military radar tower during the Cold War, as well as its prominent location high about the valley floor in Santa Clara County. The radar tower is a distinguished and locally well‐known example of utilitarian military architecture. It is a distinctive local monument of this type, associated directly with an important period in military history. The property meets Criterion 3 under the County’s ordinance for landmark designation.13 Regarding historic integrity, the Archives & Architecture report concluded that Mt. Umunhum Radar Tower (Building 102) retains sufficient integrity to a period of significance of 1959 – 1980 to be designated a landmark, stating: The Mount Umunhum Radar Tower possesses integrity of location and setting. The building has not been moved, although the surrounding buildings are in the process of being demolished at the time of the beginning of this study. Integrity of design, materials, workmanship, feeling, and association had been compromised somewhat because the radar sail and related equipment on the roof has long been removed, and technical machinery to operate the radar no longer exists. Like all decommissioned radar installations in the United States, the radar equipment was removed from the site following decommission, but the building itself retains its original appearance. The structure remains an important representation of the historic background of the former base, and has sufficient integrity to convey its history.14 4. Analysis of Significance and Integrity of Mt. Umunhum Radar Tower (Building 102) The two previous studies of the Mt. Umunhum Radar Tower (Building 102) both conclude that the building has historic significance. Page & Turnbull concluded that it is historically significant under NRHP Criterion A / CRHR Criterion 1 and NRHP Criterion C / CRHR Criterion 3, and Archives and Architecture concluded that it is historically significant under Criteria 1 and 3 of the Santa Clara County Historic Preservation Ordinance, criteria that closely mirror NRHP/CRHR Criterion A/1 and NRHP/CRNR Criterion C/3. Archvies & Architecture defined the period of 13 14 Archives & Architecture, “Historical Evaluation,” 20. Archives & Architecture, “Historical Evaluation,” 19. PEER REVIEW – MT UMUNHUM RADAR TOWER, BUILDING 102 8 JRP Historical Consulting, LLC 2015 significance as from the year construction of the tower began, 1959, through decommissioning in 1980. Page & Turnbull associated this date range with the building as well; however, their report did not define a period of significance because they did not conclude that the resource is eligible. This report agrees with the findings of historic significance in both of the previous reports, and the definition of period of significance from 1959 – 1980. The question of the eligibility of Mt. Umunhum Radar Tower (Building 102) for listing on any register hinges on whether or not it has integrity to its period of significance to convey its significance. The National Park Service provides guidance in Bulletin 15, “How to Apply the National Register Criteria for Evaluation,” about the determination of historic integrity. Bulletin 15 instructs that “only after significance is fully established can you proceed to the issue of integrity.”15 Once significance is established, Bulletin 15 lays out the following steps for determining integrity [emphasis in original]: Define the essential physical features that must be present for a property to represent its significance. Determine whether the essential physical features are visible enough to convey their significance. Determine whether the property needs to be compared with similar properties. And, Determine, based on the significance and essential physical features, which aspects of integrity are particularly vital to the property being nominated and if they are present.16 The two previous studies suggest through their discussions of significance – but do not explicitly define – the essential physical features necessary for Mt. Umunhum Radar Tower (Building 102) to convey its historic significance under the criteria for which is was found significant. Page & Turnbull considered the radar sail that was removed from the tower in 1980 to be its most important essential physical feature. Archives & Architecture noted the tower’s “prominent perch” and characterized it as a “distinctive architectural specimen” in the significance evaluation. For specific guidance related to determining essential physical features of highly technical military facilities, we turn to the statewide study, “California Historic Military Buildings and Structures Inventory,” a four‐volume study of which JRP was the primary author (hereafter “Statewide Military Context”); and the Advisory Council on Historic Preservation’s 1991 15 US Department of the Interior, National Park Service, “National Register Bulletin 15: How to Apply the National Register Criteria for Evaluation,” 1997, 45. 16 National Park Service, “National Register Bulletin 15,” 45. PEER REVIEW – MT UMUNHUM RADAR TOWER, BUILDING 102 9 JRP Historical Consulting, LLC 2015 publication, “Balancing Historic Preservation Needs with the Operation of Highly Technical or Scientific Facilities.”17 The Statewide Military Context, adopted by the California Office of Historic Preservation as the official context for evaluation of military buildings in the state, is a comprehensive study designed to be used by all Department of Defense service branches during evaluation efforts of active and former California military installations. This study analyzes the ways in which historic buildings and structures have been evaluated to date by the various military services in California, and proposes a methodological and contextual framework to guide future work. Following the classification guidelines presented in Volume III of the Statewide Military Context (Section 8.3.3), Building 102 on Mt. Umunhum represents the property type “Major Radar Arrays.” About this Cold War‐era building type, the study emphasizes: The building was more than a foundation; in most cases, the radar screens and computers were stored in the building below…If the building is found to have supported an important radar set and the building itself retains integrity to its original appearance, the possibility exists the building could be found to qualify for the National Register.18 The ACHP’s 1991 publication discusses the issue of historic integrity of scientific facilities within the context of the fact that these facilities are frequently modified or equipment removed, which can diminish or compromise integrity. The publication advises that “most scientific equipment is not viewed as a candidate for preservation in the standard historic preservation sense. Consequently, most scientists would argue that the need to replace, modify, or remove research equipment as necessary should take precedence over historic preservation considerations.” It goes on to say that decisions about preservation of these properties should take into account ways to “enhance the public’s understanding of historic scientific and technological properties.”19 The guidance in both the Statewide Military Context and the ACHP Publication on highly technical facilities support the possibility that a building such as Mt. Umunhum Radar Tower 17 JRP Historical Consulting Services, “California Historic Military Buildings and Structures Inventory, Vols. I‐IV,” prepared for US Army Corps of Engineers, March 2000; Advisory Council on Historic Preservation, “Balancing Historic Preservation Needs with the Operation of Highly Technical or Scientific Facilities,” a report to the US House of Representatives, Committee on Interior and Insular Affairs, Subcommittee on National Parks and Public Lands, and the Committee on Science, Space, and Technology, February 1991. 18 JRP Historical Consulting Services, “California Historic Military Buildings and Structures Inventory, Vol. III, Historic Context: Themes, Property Types, and Registration Requirements,” prepared for US Army Corps of Engineers, March 2000, 8‐25, 8‐26. 19 Advisory Council on Historic Preservation, “Balancing Historic Preservation Needs with the Operation of Highly Technical or Scientific Facilities,” a report to the US House of Representatives, Committee on Interior and Insular Affairs, Subcommittee on National Parks and Public Lands, and the Committee on Science, Space, and Technology, February 1991, 24. PEER REVIEW – MT UMUNHUM RADAR TOWER, BUILDING 102 10 JRP Historical Consulting, LLC 2015 (Building 102) could be considered to retain historic integrity in the absence of the radar equipment. Page & Turnbull’s conclusion that Mt. Umunhum Radar Tower (Building 102) lacks historic integrity hinges on the loss of the scientific equipment. To determine whether or not the loss of equipment is a fatal loss of historic integrity, the essential physical features necessary to convey historic significance in relation to each of the criteria must be considered and defined. 4.1. Essential Physical Features of Mt. Umunhum Radar Tower (Building 102) The previous reports both concluded that Mt. Umunhum Radar Tower (Building 102) is historically significant, either under NRHP/CRHR Criterion A/1 and/or Santa Clara County Historic Preservation Ordinance Criterion 1, for its association with important historic events. Both reports agree that the tower best represents the overall mission and purpose of Almaden AFS, and that the former radar tower is historically significant within the context of the Cold War. Of the features that define this structure as a Cold War radar tower, first and foremost is its location perched atop a high peak. Buildings placed in remote, difficult to access places such as mountaintops tend to convey associations with particular functions that require conditions like expansive viewsheds like lookout stations, or unimpeded signals like radar towers. In addition to its location, the imposing size, utilitarian form, and substantial concrete construction of the tower are all essential features that define the identity and historic use of this building. This tower was constructed for the specific purpose of supporting the AN/FPS‐24 radar sail and its associated equipment, and the size of the tower reflects the scale and weight of the equipment it was designed to support. In summary, the essential physical features of Mt. Umunhum Radar Tower (Building 102) that are necessary for it to convey its historically significant associations with Almaden AFS and the Cold War under NRHP/CRHR Criterion A/1 and Santa Clara County Historic Preservation Ordinance Criterion 1 are: Location perched atop Mt. Umunhum Size and scale Utilitarian form Concrete construction Lack of architectural embellishment The radar sail is not crucial for this building to convey its historic significance under these criteria because the essential physical features defined above all convey the function of the building in the absence of the equipment. The previous reports also concluded that Mt. Umunhum Radar Tower (Building 102) is historically significant under NRHP/CRHR Criterion C/3 and/or Santa Clara County Historic PEER REVIEW – MT UMUNHUM RADAR TOWER, BUILDING 102 11 JRP Historical Consulting, LLC 2015 Preservation Ordinance Criterion 3 as a distinctive architectural specimen built for one of the most high‐powered antennas in California at the time. Under these criteria, this building is significant because it was designed for a specific and historically important function, and its architecture, design, and location express that function. The essential physical features necessary to convey the building’s architectural identity and function are its location atop Mt. Umunhum, which was of central importance to its functionality as a radar facility; its size and form that express that it was designed to support a massive piece of equipment; its lack of any architectural ornamentation or embellishment, reflecting its strictly utilitarian function; and its concrete materials and original industrial steel windows. These features convey the historic character and function of this building. The presence of the radar sail is not essential for the building to convey its association with radar equipment at Almaden AFS during the Cold War. In summary, the essential physical features of Mt. Umunhum Radar Tower (Building 102) that are necessary for it to convey its historically significant associations with Almaden AFS and the Cold War under NRHP/CRHR Criterion C/3 and Santa Clara County Historic Preservation Ordinance Criterion 3 are: Location perched atop Mt. Umunhum location Size and scale design Utilitarian form design Concrete construction materials, workmanship Placement and materials of steel windows design, materials, workmanship Lack of architectural embellishment design, feeling 4.2. Integrity of Mt. Umunhum Radar Tower (Building 102) As noted above, National Register Bulletin 15 instructs evaluators of historic properties to determine “which aspects of historic integrity are particularly vital” after identifying the significance of the property and the essential physical features.20 The following Table 1 identifies which of the seven aspects of integrity – location, setting, design, materials, workmanship, feeling, association – are vital to retention of integrity of each of the essential physical features of Mt. Umunhum Radar Tower (Building 102): 20 National Park Service, “National Register Bulletin 15,” 45. PEER REVIEW – MT UMUNHUM RADAR TOWER, BUILDING 102 12 JRP Historical Consulting, LLC 2015 Table 1: Essential Physical Features of Mt. Umunhum Radar Tower (Building 102) and Integrity Aspects Vital to Each Feature Essential Physical Features Integrity Aspect Location perched atop Mt. Umunhum Location; Association Size and scale Design Utilitarian form Design; Association; Feeling Concrete construction Materials; Workmanship Placement and materials of steel windows Design; Materials; Workmanship Lack of architectural embellishment Design; Feeling Location: Mt. Umunhum Radar Tower (Building 102) retains integrity of location because it is in its original location atop Mt. Umunhum. This location is vital to the significance of the building because its high perch helps convey its historic association with its period as an active radar site. Design: The utilitarian, purpose‐designed character of this building is critical to its ability to convey its historic significance. The tower itself has not been subject to any substantive exterior modifications that diminish its integrity of design (Photograph 2). Photograph 2: Mt. Umunhum Radar Tower (Building 102), November 24, 2015. PEER REVIEW – MT UMUNHUM RADAR TOWER, BUILDING 102 13 JRP Historical Consulting, LLC 2015 Materials: The heavy concrete walls and industrial steel windows are critical to the function and utility of this structure designed to support a very large and heavy piece of specialized equipment. The tower has suffered no substantial losses materials and retains integrity of materials. The loss of the radar sail would only be considered a vital loss of material integrity if the sail was determined to be an essential physical feature required to convey the historic significance of the tower. The sail is not essential for the building to convey its historic significance. Workmanship: Mt. Umunhum Radar Tower (Building 102) retains integrity of workmanship because it has not been substantively altered and retains its historic materials and design. The loss of the radar sail would only be considered a vital loss of integrity of workmanship if the sail was determined to be an essential physical feature required to convey the historic significance of the tower. The sail is not essential for the building to convey its historic significance. Association: This tower retains integrity of association because it retains those features that are specific to radar towers – high mountain perch, and utilitarian, functional design. Feeling: Mt. Umunhum Radar Tower (Building 102) retains good integrity of feeling because it retains its size, scale, and utilitarian form, and it remains at its original location that can be observed from various points throughout Santa Clara County. Integrity Considerations Not Vital to the Significance of Building 102 Setting: In this case, location is more critical to understanding the historic significance of this resource than setting. During the period of significance, 1959 – 1980, the setting of the tower included nearby buildings that supported the mission and function of Almaden AFS. These buildings, which included a training building, fire hose house, and a steel tower for one of the much smaller radars, were small in size and did not contribute to the physical support of the radar sail in the manner of Mt. Umunhum Radar Tower (Building 102). These buildings are not essential to the understanding of the radar tower. Many changes have been made to the immediate setting of Building 102 including demolition of all nearby Almaden AFS buildings, and regrading at the peak of Mt. Umunhum. These changes in setting are most noticeable when viewing the tower from the mountaintop itself where it is apparent that the tower is no longer part of an active or extant Air Force installation. From a distance, however, which is how the tower has conveyed its historic significance to the broadest audience of observers throughout its history, the setting is virtually unchanged. The tower appears as it always has, an imposing bulky concrete structure atop Mt. Umunhum (Photograph 3). PEER REVIEW – MT UMUNHUM RADAR TOWER, BUILDING 102 14 JRP Historical Consulting, LLC 2015 Photograph 3: Mt. Umunhum Radar Tower (Building 102) from Bald Mountain Parking Lot. Camera facing west, November 24, 2015. 5. Conclusion After reviewing the previous reports prepared to evaluate the merits of Almaden AFS and Building 102 in particular, performing a site visit, and consulting appropriate guidance documents, this report concludes that Mt. Umunhum Radar Tower is historically significant under NRHP and CRHR Criterion A/1 and C/3 and Santa Clara County Historic Preservation Ordinance Criteria 1 and 3, and that it retains integrity to convey this historic significance. The conclusion of this study is that Mt. Umunhum Radar Tower, Building 102, is eligible for listing in the NRHP and CRHR, and qualifies as a landmark under the Santa Clara County Historic Preservation Ordinance and should be placed on the Santa Clara County Heritage Resource Inventory. PEER REVIEW – MT UMUNHUM RADAR TOWER, BUILDING 102 15 JRP Historical Consulting, LLC 6. 2015 Preparers’ Qualifications Heather Norby of JRP prepared this report. Ms. Norby holds an M.A. in History from the University of California, Berkeley. Since joining JRP in 2008 Ms. Norby’s experience has encompassed a wide range of elements of general historical research and cultural resource management. She has contributed to numerous technical reports and architectural survey and evaluation projects, and has conducted research in primary and secondary source material at public and private repositories throughout California, and at the National Archives in Washington, D.C. Ms. Norby has been involved in the preparation of numerous military projects, particularly for Edwards Air Force Base, where she has conducted research and performed fieldwork on multiple occasions; Nellis Air Force Base, where she led field teams and served as one of the primary authors of the compliance documentation; and Marine Corps Logistic Base, Barstow, where she performed fieldwork and prepared compliance documentation for over 200 Cold War‐era buildings and structures. Ms. Norby performed the fieldwork for this project and was the primary author of this report. Bryan Larson, a partner at JRP who has been with the company since 1998, served in an advisory capacity and edited this report. Mr. Larson holds an M.A. in Public History / History from California State University, Sacramento. He has specialized in the study of Cold War‐era military and high‐tech properties throughout California and the American West. He has undertaken an enormous amount of field recordation on historic sites owned or managed by federal agencies such as the United States Air Force, Army, Army Corps of Engineers, Navy, Marines, Bureau of Land Management, and Forest Service, and has conducted a substantial amount of research at many public and private archival repositories, libraries, and government agencies throughout California, Utah, Nevada, Arizona, and Washington, D.C. Based on their level of experience and education, Ms. Norby and Mr. Larson both qualify as a historian/architectural historian under the Secretary of the Interior’s Professional Qualification Standards, as defined in 36 CFR Part 61. PEER REVIEW – MT UMUNHUM RADAR TOWER, BUILDING 102 16 JRP Historical Consulting, LLC 2015 APPENDIX A Page & Turnbull 2011 Report PEER REVIEW – MT UMUNHUM RADAR TOWER, BUILDING 102 Historic Resource Study Updated Final March 9, 2011 Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, CA Prepared for Mid-Peninsula Regional Open Space District Los Altos, CA Prepared by page & turnbull, inc. 1000 Sansome Street, Ste. 200, San Francisco CA 94111 415.362.5154 / www.page-turnbull.com Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California TABLE OF CONTENTS I. INTRODUCTION............................................................................................................ 2 II. METHODOLOGY........................................................................................................... 6 APPROACH TO SURVEY, DATA COLLECTION, AND PRODUCTION OF HISTORIC CONTEXT .................................................................................................................................. 6 GUIDELINES FOR EVALUATION ............................................................................................. 8 INTEGRITY ............................................................................................................................... 11 DEFINITION OF PROPERTY TYPES ....................................................................................... 14 III. ARCHITECTURAL DESCRIPTION OF THE SITE ..................................................... 16 IV. HISTORIC CONTEXT ................................................................................................ 21 THE COLD WAR (1945 – 1991) .............................................................................................. 21 RADAR DEFENSES ................................................................................................................... 21 HISTORY OF THE ALMADEN AIR FORCE STATION ........................................................... 25 OTHER NORAD RADAR FACILITIES IN CALIFORNIA ......................................................... 37 V. EVALUATION OF THE FORMER ALMADEN AIR FORCE STATION AS A POTENTIAL HISTORIC DISTRICT ................................................................................. 49 VI. INVENTORY & BRIEF EVALUATION OF INDIVIDUAL BUILDINGS .................... 53 VII. CONCLUSION .......................................................................................................... 84 VIII. RECOMMENDATIONS............................................................................................ 85 HISTORIC INTERPRETATION (BUILDINGS 102, 108, 110).................................................. 85 POTENTIAL MROSD FACILITIES (BUILDINGS 211, 212, 884B) ........................................... 87 IX. BIBLIOGRAPHY ......................................................................................................... 88 PUBLISHED............................................................................................................................... 88 INTERNET ................................................................................................................................ 88 INTERVIEWS ............................................................................................................................. 89 OTHER ...................................................................................................................................... 89 March 9, 2011 Page & Turnbull, Inc. -1- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California I. INTRODUCTION This Historic Resource Study has been completed at the request of the Midpeninsula Regional Open Space District. It examines the history and significance of buildings located at the former Almaden Air Force Station (AFS) at the summits of Mt. Umunhum and Mt. Thayer, California. The station is located approximately six miles southeast of Los Gatos and ten miles south of downtown San Jose. This study evaluates forty-seven resources (thirty-one buildings and sixteen structures) and the site as a whole for their eligibility for listing in the National Register of Historic Places (National Register) and the California Register of Historical Resources (California Register) (Figure 1). The inclusion in this report of buildings on Mt. Thayer is an update to the original Historic Resource Study, dated 6 July 2010. See Table 1. for a list of the evaluated properties. On February 10 – 11, 2010, Page & Turnbull surveyed and digitally photographed forty-five buildings on Mt. Umunhum, accompanied by staff members from the Midpeninsula Regional Open Space District (MROSD) and Northgate Environmental Management, Inc. On February 22, 2011, Page & Turnbull surveyed the former Almaden Air Force Station Ground to Air Transmitter Receiver (GATR) complex on Mt. Thayer, which has two remaining buildings. Page & Turnbull staff then conducted research on the buildings in support of a historic context statement, which addresses the evolution of the former Almaden Air Force Station and identifies significant themes, events, and persons associated with the facility. This research was conducted in consultation with the MROSD and local Almaden Air Force Station chroniclers, who provided historical documentation, photographs, and other pertinent references. Due to the often technical nature of the concepts, direct citations and excerpts from research resources are included in the historic context statement. The context statement frames the history and significance of the individual buildings within the context of the larger facility, as well as other similar Air Force radar facility sites in California. It provided the necessary background for the evaluation of the resources and their eligibility for listing in the California Register of Historical Resources. This Historic Resource Study found none (0) of the resources eligible for listing in the California and National Registers, based upon an assessment of historic significance and integrity. The determination of eligibility for the entire site as a potential Historic District is found in V. Evaluation of the Former Almaden Air Force Station as a Potential Historic District. The determination of individual eligibility for the forty-seven resources surveyed has been summarized in March 9, 2011 Page & Turnbull, Inc. -2- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California VI. Property Inventory. Detailed individual evaluations are not included, and State of California Page & Turnbull, Inc. Department of Parks and Recreation (DPR) 523A (Primary Record) and 523B (Building, Structure, -3- Figure 1. Site Map, Former Almaden Air Force Station. and Object Record) forms were not completed. March 9, 2011 Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California (Source: Gould Architects, Mt. Umunhum Facilities Inventory and Evaluation, 1994). Table 1. Determination of Eligibility for Forty-seven Surveyed at the Former Almaden Air Force Station on Mt. Umunhum. 1 Applicable NR/CR Criteria for Historic Significance A/1 Integrity? California RegisterEligible? No No 102: Radar Tower FPS-24 (1959-1961) A/1, C/3 No No 105: Fallout Shelter (1961) N/A Yes No 108: Radar Tower MPS-14 (1962) A/1, C/3 No No 110: Training (1957) A/1 No No 112: Electrical Power Station (1960) N/A Yes No 114: Sheet, Pipe & Paint Storage (1965) N/A No No 115: Security Sentry House (1964) N/A Yes No 118: Diesel Fuel Pump (1957) N/A Yes No 119: CE [Civil Engineering] Maintenance Shop (1957) 120: Warehouse Supply & Equipment (1957) 200: Water Pump Station (1957) N/A Yes No N/A No No N/A Yes No 205: Bachelor Officers’ Quarters (1957) N/A Yes No 206: Fire Hose House (ca. 1957) N/A No No 207: Squadron Headquarters Orderly Room (1957) N/A Yes No 211: Auto Maintenance Shop, aka Motor Pool (1960) 212: NCO Open Mess (1957, addition 1975) 213: Dispensary (1957) N/A Yes No N/A Yes No N/A Yes No 215: Fire Hose House (ca. 1957) N/A No No 217: Bowling Alley (1961) N/A Yes No 225: Airman’s Dining Hall (1957) N/A Yes No 226: Fire Hose House (ca. 1957) 230: Commissary (1957; addition in 1967) N/A Yes No N/A Yes No Resource Identifier 100: Operations (1957, addition in 1959) 1 All dates checked and/or provided via Email Correspondence with Basim Jaber, 9 March 2010. Some drawings for buildings on file at MROSD are dated 1955 or 1956, but these drawings pre-date the establishment of the facility and actual construction of the buildings. March 9, 2011 Page & Turnbull, Inc. -4- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California 232: Fire Hose House (ca. 1957) N/A No No 233: Barracks, aka Airman’s Dormitory and Chapel (1957) N/A Yes No 234: Fire Hose House (ca. 1957) N/A Yes No 245: Recreation (1957) N/A Yes No 250: Auto Maintenance Storage (1958) N/A Yes No 275: Swimming Pool (1957) N/A Yes No 276: Bath House (1966) N/A Yes No 303: Paint Storage (1958) N/A Yes No 505: Carport (1958) N/A Yes No 506: Fire Hose House (ca. 1957) N/A Yes No 507: Fire Hose House (ca. 1957) N/A No No 508: Fire Hose House (ca. 1957) N/A No No 509: Fire Hose House (ca. 1957) N/A Yes No 510: Fourplex Apartment (1958) N/A Yes No 511: Fourplex Apartment (1958) N/A Yes No 512: Fourplex Apartment (1958) N/A Yes No 513: Fourplex Apartment (1958) N/A Yes No 514: Fourplex Apartment (1958) N/A Yes No 515: Triplex Apartment (1958) N/A No No 516: Commander’s House (1958) N/A Yes No 517: Triplex Apartment (1958) 700: Communications Transmitter/Receiver (GATR Building) (1962) 715/ 722: Security Sentry House (1966) N/A No No N/A No No N/A No No TELCO (1957) N/A No No March 9, 2011 Page & Turnbull, Inc. -5- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California II. METHODOLOGY The following section outlines the methodology used to frame the historic context of the former Almaden Air Force Station and evaluate the resources for listing in the California Register of Historical Resources and the National Register of Historic Places. Also included in this section is an introduction to the historic significance criteria and integrity considerations of the California Register and the National Register. APPROACH TO SURVEY, DATA COLLECTION, AND PRODUCTION OF HISTORIC CONTEXT In July 2010, Page & Turnbull completed a Historic Resource Study of forty-five resources at the former Almaden Air Force Station.2 This study consisted of site visits on February 10 – 11, 2010. Page & Turnbull updated this Historic Resource Study in February and March 2011 by surveying the Almaden Air Force Station GATR complex at Mt. Thayer, bringing the total number of surveyed properties to forty-seven. Fieldwork focused primarily on basic documentation with field notes and digital photography. No formal interior survey was conducted as part of this project, although the interiors of several buildings were accessible and briefly inspected. Page & Turnbull conducted a review of historical documents, maps, facilities records, and historic photos. Research sources are cited in the bibliography. Historic research also included consultation with Kirk Lenington, Senior Resource Planner at the MROSD, as well as interviews with local Santa Clara valley residents who have amassed a wealth of information regarding the former Almaden Air Force Station. These local sources included: Basim Jaber, who has been very active with Almaden Air Station veterans and has provided information regarding the Almaden Air Force Station site history and individual building histories. This information was derived from historic documents, photographs and oral histories, as well as correspondence with former Air Force staff. David Schwaderer, who provided information about the Almaden Air Force Station site history. Page & Turnbull staff member Christina Dikas is the primary author of this study. She meets the Secretary of the Interior’s Professional Qualifications Standards in Architectural History. 2 March 9, 2011 Page & Turnbull, Inc. -6- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California The evaluations in this report are confined to buildings and radar structures. Ancillary structures and objects deemed to have no potential for historic significance were not surveyed or evaluated. These facilities include the following: 1: Flag Pole (1957) 103: Helicopter Pad (1962) 140, 141, 142, 143: Sewage Septic Tanks (1957) 310, 311: Sewage Septic Tanks (1957) 415: Storage for Heating Fuel (1957) 420: Storage for Gasoline (1958) 421: Vehicle Fueling Station/Pump (1958) 600 Series: water pump stations, storage tanks, and three earthen dam facilities that harvested water from nearby Lake Elsman and watershed (1957) 884B: Water Tank, Steel (1958) Similarly, this survey determined that several buildings and facilities are no longer extant, and are therefore not evaluated in this report. They include: 104: Paint Storage 106: Water Storage Tank 107: Radio Tower FPS-90, foundation extant 117: Diesel Storage A&B 124: Fire Hose House 126: Fire Hose House 127: Fire Hose House 128: Fire Hose House 129: Fire Hose House 130: Fire Hose House 209: Fire Hose House 711: Heating Fuel Oil Storage 712: Sewage Septic Tank 713: Water Storage Tank 884A: Water Tank, Wood (1957) March 9, 2011 Page & Turnbull, Inc. -7- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California GUIDELINES FOR EVALUATION National Register of Historic Places The National Register is the nation’s most comprehensive inventory of historic resources. The National Register is administered by the National Park Service and includes buildings, structures, sites, objects, and districts that possess historic, architectural, engineering, archaeological, or cultural significance at the national, state, or local level. Typically, resources over fifty years of age are eligible for listing in the National Register if they meet any one of the four criteria of significance and if the resources retain historic integrity. However, resources under fifty years of age can be determined eligible for listing in the National Register if it can be demonstrated that they are of “exceptional importance,” or if they are contributors to a potential historic district. The National Register Criteria for Evaluation are described in full in Code of Federal Regulation, Title 36, Part 60 and in National Register Bulletin Number 15: How to Apply the National Register Criteria for Evaluation. There are four criteria under which a structure, site, building, district, or object can be considered eligible for listing in the National Register. These criteria are: Criterion A (Event): Properties associated with events that have made a significant contribution to the broad patterns of our history; Criterion B (Person): Properties associated with the lives of persons significant in our past; Criterion C (Design/Construction): Properties that embody the distinctive characteristics of a type, period, or method of construction, or that represent the work of a master, or that possess high artistic values, or that represent a significant distinguishable entity whose components lack individual distinction; and Criterion D (Information Potential): Properties that have yielded, or may be likely to yield, information important in prehistory or history. California Register of Historical Resources The California Register of Historical Resources (California Register) is an inventory of significant architectural, archaeological, and historical resources in the State of California. Resources can be listed in the California Register through a number of methods. State Historical Landmarks and National Register-listed properties are automatically listed in the California Register. Properties can also be nominated to the California Register by local governments, private organizations, or citizens. The evaluative criteria used by the California Register for determining eligibility are closely based on those developed by the National Park Service for the National Register of Historic Places. March 9, 2011 Page & Turnbull, Inc. -8- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California In order for a property to be eligible for listing in the California Register, it must be found significant under one or more of the following criteria: • Criterion 1 (Events): Resources that are associated with events that have made a significant contribution to the broad patterns of local or regional history, or the cultural heritage of California or the United States. • Criterion 2 (Persons): Resources that are associated with the lives of persons important to local, California, or national history. • Criterion 3 (Architecture): Resources that embody the distinctive characteristics of a type, period, region, or method of construction, or represent the work of a master, or possess high artistic values. • Criterion 4 (Information Potential): Resources or sites that have yielded or have the potential to yield information important to the prehistory or history of the local area, California, or the nation. • Resources eligible for the National Register are automatically listed in the California Register of Historical Resources. The “Fifty Year Rule” and Criteria Consideration G According to National Register evaluation criteria, resources that are less than fifty years old must meet “Criteria Consideration G: Properties that Have Achieved Significance within the Last Fifty Years” in order to be eligible for listing in the National Register. Criteria Consideration G states that “[a] property achieving significance within the last fifty years is eligible if it is of exceptional importance.”3 In order for a property to be evaluated under Criteria Consideration G, there must be sufficient historical perspective to determine that the property is exceptionally important, as well as a comparison among other related properties within a geographic area to determine if the property qualifies as exceptionally important. In addition, the property must first meet one of the four National Register significance criteria. Properties which have achieved significance within the past fifty years can also be eligible for the National Register if they are an integral part of a qualified district. As stated in the National Register Bulletin: Guidelines for Evaluating Properties that Have Achieved Significance Within the Past Fifty Years: 3 National Park Service, National Register Criteria for Evaluation, p. 41. March 9, 2011 Page & Turnbull, Inc. -9- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California The rationale or justification for exceptional importance should be an explicit part of the statement of significance. It should not be treated as self-explanatory… The second section should contain the justification as to why the property can be determined to be of exceptional importance. It must discuss the context used for evaluating the property. It must demonstrate that the context and the resources associated with it can be judged to be “historic.” It must document the existence of sufficient research or evidence to permit a dispassionate evaluation of the resource. Finally, it must use the background just presented to summarize the way in which the resource is important.4 Examples of properties that have been listed according to Criteria Consideration G are the Cape Canaveral launch pad, from which the first humans traveled to the moon, the Chrysler Building in New York, for its significance as the epitome of “Style Moderne” architecture, and the home of nationally prominent playwright Eugene O’Neill.5 Though the National Register of Historic Places requires that resources less than fifty years of age show “exceptional importance,” this is not the case with the California Register. According to the California Office of Historic Preservation: In order to understand the historic importance of a resource, sufficient time must have passed to obtain a scholarly perspective on the events or individuals associated with the resource. A resource less than fifty years old may be considered for listing in the California Register if it can be demonstrated that sufficient time has passed to understand its historical importance.6 To date, none of the resources at the former Almaden Air Force Station have been assessed for their historical significance. Consequently, none of these resources have been listed in or found eligible for the California Register or the National Register. Special Considerations in the Evaluation of Highly Technical and Scientific Facilities The highly technical nature of the radar facilities at the former Almaden AFS presents unique issues for determining the resources’ historical significance and level of integrity. Since the character of highly technical and scientific facilities includes the constant evolution of technology and use, an evaluation of historic significance and integrity must be based upon a firm understanding of a resource’s functional history, historic context, character, and reason for the changes over time. Marcella Sherfy and W. Ray Luce, National Register Bulletin Number 22: Guidelines for Evaluating and Nominating Properties that Have Achieved Significance Within the Past Fifty Years (Washington D.C.: National Park Service, 1998), p. 11. 5 Ibid. 4 6 California Office of Historic Preservation, Technical Assistant Series No. 7, How to Nominate a Resource to the California Register of Historic Resources (Sacramento, CA: California Office of State Publishing, 4 September 2001) .11 March 9, 2011 Page & Turnbull, Inc. -10- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California One of the earliest public documents to address this issue was the Advisory Council on Historic Preservation’s “Balancing Historic Preservation Needs with the Operation of Highly Technical or Scientific Facilities,” published in 1991. This document addressed the issue of stewardship of historic resources within scientific and technical facilities. These facilities are faced with the challenge of balancing ongoing technical advancements—which often involve major alterations to historically significant buildings, equipment, and spaces—with consideration of the effects of these activities on historic properties. In terms of evaluating scientific or technical properties, questions arise regarding the resources’ direct connection to a significant historic context and the ability of the resources to convey this connection through their physical features. These two issues, determining the historic context and assessing historic integrity, are the main challenges in evaluating the eligibility of the radar facilities under review at the former Almaden Air Force Station. Scientific and highly technical resources are often significant because of their indirect contributions to other events or resources and larger systems and discoveries. However, this analysis can prove overly broad because it can be argued that nearly every technical resource in a network is related to one particular operational mission. In accordance with the methodology used by Page & Turnbull in evaluating resources at other mid-twentieth century scientific and technical facilities, only those properties that had a direct association with an important event can be considered significant under California Register criteria. INTEGRITY In addition to qualifying for listing under at least one of the California Register criteria for historic significance, a resource must also retain historic integrity. Integrity is defined as “the authenticity of an historical resource’s physical identity evidenced by the survival of characteristics that existed during the resource’s period of significance,” or more simply defined as “the ability of a property to convey its significance.”7 The process of determining integrity is similar for both the California Register and the National Register. The same seven variables or aspects that define integrity— location, design, setting, materials, workmanship, feeling and association—are used to evaluate a resource’s eligibility for listing in the California Register and the National Register. According to the National Park Service’s National Register Bulletin Number 15: How to Apply the National Register Criteria for Evaluation, the aspects of integrity are defined as follows: California Office of Historic Preservation, Technical Assistance Series No. 7: How to Nominate a Resource to the California Register of Historic Resources (Sacramento, CA: California Office of State Publishing, 4 September 2001), p. 11; National Park Service, National Register Bulletin: How to Apply the National Register Criteria for Evaluation (Washington D.C.: National Park Service, 1997), p. 44. 7 March 9, 2011 Page & Turnbull, Inc. -11- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California Location is the place where the historic property was constructed. Design is the combination of elements that create the form, plan, space, structure and style of the property. Setting addresses the physical environment of the historic property inclusive of the landscape and spatial relationships of the building(s). Materials refer to the physical elements that were combined or deposited during a particular period of time and in a particular pattern of configuration to form the historic property. Workmanship is the physical evidence of the crafts of a particular culture or people during any given period in history. Feeling is the property’s expression of the aesthetic or historic sense of a particular period of time. Association is the direct link between an important historic event or person and an historic property. Integrity is a “yes” or “no” determination. An historic property either retains integrity or it does not. To retain historic integrity, a property will often possess several, if not all of the aforementioned aspects. Specific aspects of integrity may also be more important, depending on the criteria for which it is significant. Most of the buildings at Mt. Umunhum show deterioration due to weathering and neglect. However, it is important to note that historic integrity is not synonymous with condition. A building or structure can possess all or many of the seven aspects of integrity, even if the condition of the materials has degraded. Condition becomes a more important factor when weathering or vandalism has led to the outright loss of historic materials. Assessing Historic Integrity Scientific facilities or highly technical resources are often significant for the events that took place within them, rather than for their physical characteristics, which may have been significantly altered over time. This issue presents a challenge when evaluating the historic integrity of a scientific property, since a resource must be found significant within an historic context and retain the physical characteristics that best express this historical significance in order to be eligible for listing in the California Register. According to the National Park Service’s National Register Bulletin: How to Apply the National Register Criteria for Evaluation (which also applies to California Register criteria): March 9, 2011 Page & Turnbull, Inc. -12- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California To retain historic integrity a property will always possess several, and usually most, of the aspects. The retention of specific aspects of integrity is paramount for a property to convey its significance. All properties change over time. It is not necessary for a property to retain all its historic physical features or characteristics. The property must retain, however, the essential physical features that enable it to convey its historic integrity. The essential physical features are those features that define both why a property is significant (Applicable Criteria and Areas of Significance) and when it was significant (Periods of Significance).8 For the forty-seven resources reviewed at the former Almaden AFS, the aspects of integrity deemed to be of the highest value in the evaluation process were workmanship and association. These two aspects allowed for latitude in the evaluation of the other aspects of integrity, which may have been significantly altered. As defined previously, workmanship is the physical evidence of the crafts of a particular culture or people during any given period in history or prehistory, and association is the direct link between an important historic event or person and a historic property. Although workmanship is often associated with traditional crafts and construction techniques, it can be adapted to suit the evaluation of scientific and technical resources. Examples of workmanship for these types of facilities include the presence of specialized equipment and other technological resources, such as computer stations, specialized infrastructure, large-scale cranes, vacuum spheres, and cable trays. These resources are often vital in the facility’s operational mission, and serve as the physical evidence of work conducted in a particular time and place. In many cases, equipment and technological resources function as the primary historic elements within technical facilities, and the building housing them is often treated as a shell adapted to these resources. While the character of the equipment may change or evolve over time, the function of this equipment or technology remains constant despite the changes in appearance or design. Therefore, in evaluating the workmanship of radar facilities, significant equipment that played a role in the history of Cold War military programs must be noted in the context statement and integrity evaluation. Although the structure or building may physically change and evolve over time, if the significant equipment and technological resources used in that military function still exist, even if altered, then a resource may retain integrity of workmanship. 8 Ibid., 44; 46. March 9, 2011 Page & Turnbull, Inc. -13- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California In a scientific or highly technical facility, integrity of workmanship is defined as the constant evolution of equipment and technology constructed for a specific goal. This technology often results in significant events or associations that are embodied within a place. The National Park Service defines this connection as the integrity of association – the direct link between an important historic event or person and an historic property. The National Park Service recognizes integrity of association as being subjective, and often, ephemeral in nature. The integrity of association of a scientific or highly technical facility is vital to convey its significance because some identifiable link to the significant event or person is essential. Integrity of association is not solely defined by its aesthetic attributes, which are identified as the integrity of feeling. Technical facilities often lack this integrity of feeling, due to the evolution of the physical characteristics, which would have originally defined a building, structure or object. The integrity of association is more closely tied to the place. Therefore, integrity of association is required in order to convey a scientific or highly technical facility’s connection to a past discovery or achievement. DEFINITION OF PROPERTY TYPES At the former Almaden Air Force Station, properties can be divided into three general uses: Special Military Purpose (radar operation), Support (functional support to the radars and operation of the station as a whole), and Ancillary (sheds, outbuildings, etc.). Further description of the buildings can be found in IV. Architectural Description of the Site. Special Military Purpose Facilities Buildings designed as purpose-built military facilities are located in the Operations area on Mt. Umunhum and the GATR site on Mt. Thayer. They generally include the largest building type (in size) found at Almaden AFS. These buildings and structures housed or supported the technical equipment directly related to performing radar military operations. The resources were constructed with either thick reinforced concrete walls, concrete masonry unit (CMU) construction, or steel structures. None of the buildings are rendered in a particular style; they are utilitarian in appearance with no ornamentation and few windows. Significance of Special Military Purpose Facilities These facilities may be considered significant, as they contained the instruments used for radar operation and communication with other Air Force personnel. They represent the primary purpose of the facility. Some Special Military Purpose facilities have unique designs created specifically for their particular functions. March 9, 2011 Page & Turnbull, Inc. -14- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California Support and Residential Facilities Support facilities are located in the Operations, Cantonment, and GATR areas. They include administrative offices, cafeteria, commissary, gymnasium, and maintenance shops. Housing in the Cantonment includes barracks and family apartments. Many of these are pre-fabricated steel buildings, while others are of CMU or wood frame construction. Most of these buildings are utilitarian in appearance, though the apartments are designed in a simple modern style. Significance of Support and Residential Facilities Support and Residential Facilities are likely not individually significant because, as their names indicate, they provide supportive services to the Special Military Purpose Facilities. As individual resources, they do not best represent the purpose of Almaden AFS or any important events that may have occurred there. While several are representative examples of the Modern style, they are not particularly unique or outstanding in their designs. Ancillary Facilities Ancillary buildings include sheds and outbuildings, and primarily consist of simple wood-frame fire house shelters. The buildings lack an architectural style and are utilitarian in nature. Significance of Ancillary Facilities These facilities are not considered significant. They support the basic functions of the facility as a whole, but like support facilities, they do not individually represent the primary purpose of Almaden AFS or any important events that may have occurred there. March 9, 2011 Page & Turnbull, Inc. -15- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California III. ARCHITECTURAL DESCRIPTION OF THE SITE The former Almaden Air Force Station is located at the peak of Mt. Umunhum in the Santa Cruz Mountains, approximately six miles southeast of Los Gatos, California (Figures 2 and 3). The station is constructed at an elevation of approximately 3,400 feet, and is accessed by following an 11.5 mile winding route past Guadalupe reservoir. Mt. Umunhum and Mt. Thayer are located towards the southern end of the Sierra Azul Open Space Preserve, which is owned and managed by the Midpeninsula Regional Open Space District. The primary facility on Mt. Umunhum is roughly divided into three sections: the operations area, the cantonment area, and the family housing area. The operations area is located at the east end of the site, and is divided into an upper and a lower section. The upper operations area, located on the highest peak of the site, housed the radar operations facilities, including the operations building (Building100), storage sheds, a concrete radar tower for the AN/FPS-24 (Building 102), a steel tower structure for the AN/MPS-14 (Building 108), and a training building (Building 110). The lower section of the operations area, located southwest of the peak, includes a supply warehouse (Building 120), the power station (Building 112), the civil engineering maintenance shop (Building 119), a TELCO building paint storage (Building 114) and a diesel fuel pump building (Building 118). The cantonment area is located at a lower elevation to the southwest, near the main entrance to the site. It includes the site administration facilities and facilities that supported the service-people and their families. The squadron headquarters/orderly room building (Building 207) and the bachelor officers quarters (Building 205) are located on a slight hill to the east in the cantonment area. A water pump is situated across the parking lot from these two buildings below a large metal water tank (once the site of two water tanks). Community services are located at the center of the cantonment area, including a dispensary (Building 213), NCO open mess (Building 212), automobile maintenance facility (Building 211), recreation building (Building 245), swimming pool and bathhouse (Buildings 275 and 276), bowling alley (Building 217), barracks/chapel/hobby shop (Building 233), commissary (Building 230) and airmen’s dining hall (Building 225). Down the hill to the west is the family housing residential section, which includes a long carport (Building 505), five fourplex apartments (Buildings 510, 511, 512, 513, 514), two triplex apartments (Buildings 515 and 517), one single-family residence (Building 516), and several fire hose houses for fire protection. A sewage treatment area with oxidation ponds is located northwest of the cantonment. March 9, 2011 Page & Turnbull, Inc. -16- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California The GATR complex is located one mile west on Mt. Thayer. Only two buildings remain: a small security sentry house (recorded as both Building 715 and 722) and the Communications Transmitter/Receiver building, also known as the GATR Building (Building 700). Surrounding Building 700 is an “antenna farm” of wood poles with anchoring cables. Figure 2. Aerial, Almaden Air Force Station, ca. 1960s. Cantonment in the western foreground and radars to the east (several steel barracks buildings were removed in the 1970s). (Source: http://www.radomes.org/museum/) Figure 3. Aerial, former Almaden Air Force Station on Mt. Umunhum in relation to GATR facility on Mt Thayer, ca. 2010. (Source: Microsoft Corporation, www.bing.com) March 9, 2011 Page & Turnbull, Inc. -17- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California The buildings at the former Almaden AFS feature reinforced concrete, concrete masonry unit (CMU), or wood frame construction. Notably, the station also includes a number of prefabricated steel “Butler buildings,” which first came into widespread use by the military during World War II (Figure 4). Built by the Butler Manufacturing Co., Butler buildings feature an integrated structural steel building system with components that have been pre-engineered and fabricated based on the designer's specifications. They are long and narrow, with concrete foundations, corrugated metal siding, divided-light steel awning windows, and metal gable roofs. The steel Butler buildings are located in both the operations and cantonment areas of the station. They include the Training Building (Building 110), one section of the Operations building (Building 100), CE Maintenance Shop (Building 119), the Squadron Headquarters/Orderly Room (Building 207), Bachelor Officers Quarters (Building 205), Dispensary (Building 213), NCP Open Mess (Building 212), the Airmen’s Dining Hall (Building 225), Commissary (Building 230), and Barracks/Chapel (Building 233). Five other barracks buildings were once located in the cantonment, but only their concrete footing foundations remain today. Figure 4. Butler Manufacturing Co. emblem at the gable peak of the Commissary (Building 230). (Source: Page & Turnbull, February 2010). There is also one steel structure in the operations area—the tower for the AN/MPS-14 height finder radar. This structure has four legs and a small metal enclosure at the top of the platform, which is accessed by metal stairs on the east side. The radar unit is no longer located above the tower. The concrete masonry unit (CMU) buildings are also located in both the operations and cantonment areas, as well as at the GATR complex on Mt. Thayer. They include two sections of the Operations Building (Building 100), Warehouse Supply and Equipment (Building 120), the Electrical Power Station (Building 112), TELCO, Bowling Alley (Building 217), Recreation Building (Building 145), March 9, 2011 Page & Turnbull, Inc. -18- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California Paint Storage (Building 303), and the Communications Transmitter/RCVR building at GATR (Building 700). The AN/FPS-24 tower is a behemoth of reinforced concrete construction. Figure 5. The TELCO, Security, Diesel Fuel Pump, Figure 6. The road leading east to the and spill containment pool at the east end of the Operations Building and radar towers. operations area. (Source: Page & Turnbull, February 2010). (Source: Page & Turnbull, February 2010). The wood frame buildings and structures are primarily located in the family housing section and the cantonment area, though there is a wood frame Sheet, Pipe and Paint Storage building (Building 114) in the operations area and a wood-frame security sentry house (Building 715/722) at the GATR complex. The apartment buildings, single family residence, and fire hose houses are all constructed with wood frames (Figure 7). The apartment buildings are of a typical Modern style common in California during the 1950s and 1960s, with flush wood doors, sliding aluminum-sash windows, and open stairwells ornamented with vertical wood slats. They appear to have been designed by the architecture firm of Porter, Urquhart, McCreary & O’Brien. March 9, 2011 Page & Turnbull, Inc. -19- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California Figure 7. Apartments on the hill at the west end of the site. (Source: Page & Turnbull, February 2010). March 9, 2011 Page & Turnbull, Inc. -20- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California IV. HISTORIC CONTEXT The following section provides a center-specific discussion of the former Almaden Air Force Station’s contribution to the U.S. Air Force’s defense efforts during the Cold War. Included in this section is a brief history of the Cold War, an outline of the development of the Air Defense Command (ADC) and the North American Aerospace Defense Command (NORAD), and an historic context statement specific to the former Almaden Air Force Station.9 THE COLD WAR (1945 – 1991) With the conclusion of World War II in 1945, disagreements arose between the Allied powers over the future political and economic direction of the conquered nations. These tensions soon developed into the “Cold War,” so named because it was not characterized by direct armed conflict, but rather by the buildup of nuclear and missile defense systems, spying, and economic competition. This indirect conflict involved multiple nations, but was primarily a contest between the Soviet Union and the United States. The Cold War was not fully resolved until the Soviet Union collapsed and was officially dissolved in 1991.10 During the Cold War, both the Soviet Union and the United States vastly expanded their respective weapons capabilities, first with long-range nuclear bombers, and later with the development of Intercontinental Ballistic Missile (ICBM) systems capable of delivering nuclear warheads to targets located thousands of miles away. These developments compelled both nations to devise new defense systems, including significant investments in radar technology that could detect and help destroy incoming threats.11 RADAR DEFENSES As part of its defense systems, the United States—in cooperation with Canada—built and maintained extensive radar networks. These included the interim LASHUP and PERMANENT networks throughout the U.S. (1951); 35 radar sites on the PINETREE line (1951) across mid-Canada; and the Distant Early Warning System, or DEW line (1954), in northern Canada.12 The Semi-Automatic Ground Environment (SAGE) system, established in 1958, allowed the military to locate enemy aircraft in U.S. airspace through an automated system that could receive and analyze data from many For a comprehensive historic context on Cold War radar defense, see: David F. Winkler, Searching the Skies: The Legacy of the United States Cold War Defense Radar Program (Champaign, Il: United States Air Force Headquarters Air Combat Command, June 1997). 10 “Cold War,” Wikipedia. Accessed on 2 March 2010, http://en.wikipedia.org/wiki/Cold_War 11 “NORAD Fact Sheet,” Online Air Defense Radar Museum. Accessed on 23 February 2010, http://www.radomes.org/museum/data/newsletters/NORAD79-1.jpg 12 National Park Service, Western Region. Historic American Buildings Survey: Mill Valley Air Force Station, HABS No. CA-2615 (San Francisco, CA: National Park Service, 1995) 4. 9 March 9, 2011 Page & Turnbull, Inc. -21- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California stations simultaneously.13 Along with other radar networks, management of the SAGE system was incorporated within the North American Aerospace Defense Command (NORAD), inaugurated in 1958. At its height in the early 1960s, NORAD employed about 120,000 individuals and commanded an annual budget of $1.4 billion.14 Its mission was to protect U.S. airspace from invasion, warn of weapons entering that airspace, and intercept any attacks that were launched from the air, sea, or ground. Radar was originally developed by the U.S. Navy in 1940. The term is an acronym for Radio Detection and Ranging, indicating its use of electromagnetic radio waves to detect the presence of objects at long distances.15 Radar systems transmit radio waves and use any returns, or bounces, to pinpoint the location of objects. By the 1950s, radar had become sufficiently advanced to allow tracking of airborne missiles. During the Cold War, Air Force radar stations generally operated three types of radars: a general surveillance radar, a search radar, and a long-range height-finder radar (Figures 8 and 9). The search radars detected potential hostile aircraft and told the range and bearing, while the height-finder radars rocked up and down to find the altitude of objects in the airspace.16 These two types of radars worked together to triangulate the specific location of objects. The radars each went through several upgraded iterations as technology improved over the years. The following includes direct citations from the Federation of American Scientists about some of the more common radars used at Cold War era Air Force Stations: General Surveillance Radar: AN/FPS-20, AN/FPS-66, AN/FPS-67, AN/FPS-93 Production of the AN/FPS-20 Surveillance Radar began in 1956. This dualmodulator, fixed station, general surveillance system, developed by RADC [Air Force Rome Air Development Center] became the main surveillance radar for the continental United States. Equipped for dual-channel operations with a klystron transmitter, this system provided long-range surveillance capability. This Bendixbuilt radar was an AN/FPS-3 search radar with an AN/GPA-27 installed. Designed to operate in the L-band frequencies of 1250 to 1350 MHz, the radar had a range of over 200 miles. By the late 1950s, this radar dominated the U.S. radar defense network, with deployment continuing into the early 1960s. In June 1959 Bendix received a contract to provide private industry's MK-447 [the same system as the military AN/GPA-103] and MK-448 [AN/GPA-102] antijam packages to the radars. With the addition of these packages, the Air Force re-designated the radars Ibid. “The Mission of ADC,” Aerospace Defense Command Pamphlet 190-1, September 1963. Online Air Defense Radar Museum. Accessed on 23 February 2010 15 “Radar,” Wikipedia. Accessed on 2 March 2010, http://en.wikipedia.org/wiki/radar 16 David F. Winkler, Searching the Skies: The Legacy of the United States Cold War Defense Radar Program (Champaign, Il: United States Air Force Headquarters Air Combat Command, June 1997) 30. 13 14 March 9, 2011 Page & Turnbull, Inc. -22- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California as AN/FPS-66 [AN/GPA-102] and AN/FPS-67 [AN/GPA-103]. The AN/FPS-93 search radar system is a modified AN/FPS-20 with the addition of the Diplex Gating Unit (DGU) developed by Raytheon for use in the SAGE system. Figure 8. AN/FPS-20, location and date unknown. (Source: http://www.fas.org/nuke/guide/usa/airdef/an-fps-20.jpg) Search Radar: AN/FPS-24, AN/FPS-26, AN/FPS-27, AN/FPS-28, AN/FPS-35 The Frequency Diversity Radar program was a major radar developmental program at RADC. Some of the prototypes developed as part of it included the AN/FPS-26, the AN/FPS-27, the AN/FPS-28, and the AN/FPS-35, in addition to the AN/FPS24 frequency diversity radar. This equipment was designed to succeed existing SemiAutomatic Ground Environment (SAGE) radar systems, which had served as the backbone of air defense of the CONUS, in order to provide enhanced electronic counter countermeasures (ECCM) capability. March 9, 2011 Page & Turnbull, Inc. -23- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California Figure 9. AN/FPS-24, location and date unknown. (Source: http://www.fas.org/nuke/guide/usa/airdef/an-fps-24.jpg) AN/FPS 24: General Electric built an FD search radar designed to operate in the Very High Frequency (VHF) at 214 to 236 MHz. There were problems with this radar at the test site at Eufaula, Alabama, in 1960. These problems required many modifications. Additional problems occurred when deployment was attempted in 1961. When the radar finally deployed, bearing problems often occurred due to the eighty-five ton antenna weight. Twelve systems were built between 1958 and 1962. The AN/FPS-24 radar, utilizing a hydrostatic bearing, became operational in the SAGE system on 30 June 1968. The development of the bearings was the work of Goodyear Aerospace, under contract with Air Force Rome Air Development Center RADC. AN/FPS 26: Avco Corporation built this height-finder radar that operated at a frequency of 5400 to 5900 MHz. On 20 January 1960, after testing, RADC accepted the AN/FPS-26 air defense radar from AVCO, the contractor, stipulating that the contractor must correct certain component deficiencies. This radar deployed in the 1960s. Long-Range Search Radar: AN/FPS- 7 In the mid-1950s, General Electric developed a radar with a search altitude of 100,000 feet and a range of 270 miles. The AN/FPS-7 radar system was one of the first stacked-beam systems to combine both the search and the height-finding capabilities to perform ground-controlled intercept functions. Designed to operate in the L-band at 1250 to 1350 MHz, the radar deployed in late 1959 and the early 1960s. The AN/FPS-7 was used for both air defense and air traffic control in New York, Kansas City, Houston, Spokane, San Antonio, and elsewhere. In the early 1960s, a modification called AN/ECP-91 was installed to improve its electronic countermeasure (ECM) capability. About thirty units were produced. Long-Range Height Finder Radar: AN/FPS-6, AN/FPS-90 The AN/FPS-6 radar, developed at RADC, was the first long-range height finder radar employed at all Semi-Automatic Ground Environment (SAGE) locations. This system had a maximum range of 200 nautical miles and a height-finding March 9, 2011 Page & Turnbull, Inc. -24- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California capacity of 75,000 feet within an angle limit of minus 2 to plus 32 degrees. The AN/FPS-90 is a modified AN/FPS-6B.17 The highest period of tension for the United States during the Cold War was the 1962 Cuban Missile Crisis, when it was discovered that the Soviet Union was in the process of placing nuclear missiles on the island. Threats of nuclear war slowly diminished after that event, which was resolved without armed conflict. Between 1963 and 1979, the United States and Canada cooperated on reducing the size of NORAD facilities and eliminating obsolete sites, as air defense of the United States shifted more to the Air National Guard and Air Force Reserve. The Aerospace Defense Command (ADC), the U.S.’s operating arm of NORAD, was inactivated in 1979 and replaced with the Tactical Air Command (TAC), which consolidated air defense operations. The 1979 Joint U.S.-Canada Air Defense Study paved the way to modernize NORAD through the development of new radar lines and the use of Airborne Warning and Control System (AWACS) aircraft for improved performance.18 The development of these new technologies made many of the older radar facilities obsolete, and most were closed over the coming years. HISTORY OF THE ALMADEN AIR FORCE STATION With the outbreak of the Cold War, as well as the Korean War in 1950, the U.S. Army and U.S. Air Force began reestablishing air defenses to protect the United States against manned bomber attacks from the Soviet Union. Some air defense radar sites that were used in World War II were reactivated, and many new sites were established. Almaden Air Force Station was a U.S. Air Force early warning radar base that operated from 1958 to 1980. It was constructed as part of NORAD to keep watch over Northern California’s airspace during the Cold War. In order to develop the site, the U.S. Air Force acquired, between 1957 and 1962, 48.02 fee acres, 43.72 easement acres, and 26.62 lease acres (total acreage of 118.36) from several private individuals and the San Jose Water Works (SHWW), a public utility company.19 17 “Strategic Air Defense Systems,” Federation of American Scientists, Website http://www.fas.org/nuke/guide/usa/airdef/ 18 “Aerospace Defense Command,” Wikipedia. Accessed on 3 March 2010, http://en.wikipedia.org/wki/Aerospace_Defense_Command 19 U.S. Army, “Defense Environmental Restoration Program Formerly Used Defense Sites, Findings and Determination of Eligibility, Almaden Air Force Station (Z-96), Santa Clara, California, Site No. J09CA099900” (2 December 1991). March 9, 2011 Page & Turnbull, Inc. -25- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California Figure 10. The 682nd Radar Squadron’s emblem. (Source: http://www.radomes.org/museum/) Radar Facilities and Responsibilities The station was established on 24 July 1957, when the 682nd Aircraft Control and Warning (AC&W) Squadron was assigned to the site (Figure 10). However, funding shortfalls at the Air Defense Command delayed construction, and the squadron was not officially transferred until 7 October 1957.20 Almaden AFS subsequently became fully operational on 21 March 1958 as part of the San Francisco Air Defense Sector.21 It was known as Transmitter Site M-96; AC&W Site M-96; Call Mountain Radio Relay Annex; and Almaden Air Force Station (Z-96).22 The radar facilities were clustered at the east end of the complex on the highest point of the mountain. These buildings included the radar towers, operations building, and generator buildings. The first operational radars were an AN/FPS-20 search radar and AN/FPS-6A height finder that had been constructed in 1957. The AN/FPS-6A was located immediately north of the Operations Building (Building 100), and designated as Building 125. The radar was removed in 1963, and the structure is no longer extant (Figure 11).23 “Almaden Air Force Station,” Wikipedia. Website accessed on 16 March 2010 from: http://en.wikipedia.org/wiki/Almaden_Air_Force_Station 21 682nd Radar Squadron, 2. 22 U.S. Army. 23 Email correspondence with Basim Jaber, 23 March 2010. Information drawn from accounts by veterans who completed the upgrades and moves. 20 March 9, 2011 Page & Turnbull, Inc. -26- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California Figure 11. Operations (Building 100) with AN/FPS-20 radome to the left, AN/MPS-14 radar to at center, and AN/FPS-6A to the far right, ca. 1959-1960. (Source: http://www.radomes.org/museum/) A second AN/FPS-6A height-finder radar was installed as Building 107 in 1958, and upgraded to an AN/FPS-90 in the spring of 1963. An AN/MPS-14 radar (Building 108) was constructed in 1962 and came online in 1963. The AN/MPS-14 was constructed at the same as the AN/FPS-6A, but was constructed to be mobile rather than fixed. The AN/FPS-20 search radar was situated west of the Operations Building where the helipad is currently located. The radar was housed in a domed structure called a radome. This radar was replaced by a massive AN/FPS-24 search radar atop Building 102—itself an imposing five-story concrete tower constructed between 1959 and 1961. This building also included a height finder shop on the second floor (Figure 12). The AN/FPS-24 was deployed by the manufacturer in 1961, but bearing problems often occurred due to the eighty-five ton weight of the antenna. In subsequent years, the radar was rarely updated because of difficulties arising from its enormous size.24 24 Telephone interview with Basim Jaber, local chronicler of the former Almaden AFS, 2 March 2010. March 9, 2011 Page & Turnbull, Inc. -27- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California Figure 12. AN/FPS-24 (Building 102) at left, Building 110, and AN/FPS-90 (Building 108), ca. 1960s. (Source: http://www.radomes.org/museum/) The AN/FPS-24 system at Almaden was the second of twelve production models built between 1958 and 1962. The radar became operational in 1962, and had a 250-mile range—considerably stronger than the 200-mile range of the Air Force radars at Mill Valley and Cambria. The AN/FPS-20 radome was removed after 1961, and the structural footings were shaved to the ground.25 The AN/FPS-24 radar “sail” was removed in June 1980, and the radars for the AN/MPS14 and AN/FPS-90 were removed about the same time.26 The Ground to Air Transmitter Receiver (GATR), or communications function, was originally located in Building 110 (Figures 13 and 14). The communications equipment was connected to the Operations Building (Building 100) via cable trough. Following the construction of the AN/FPS-24 tower, the GATR function needed to be moved so that the UHF frequency of the radar would not interfere with the transmitter communication equipment. A new GATR site was constructed in May 1962, about a mile away on Mt. Thayer. Building 110 was then converted to the D.E. supply room. 27 “D.E.” was the Air Force office symbol at the time for “Civil Engineering.” When Building 110 was Email correspondence with Basim Jaber, 23 March 2010. Information based upon historic photographs and veterans’ accounts. 26 Email correspondence with Basim Jaber, 23 March 2010. A friend moved onto the mountain in June 1980 and recalls watching the radars being removed immediately after moving. 27 Telephone interview with Basim Jaber, local chronicler of the former Almaden AFS, 2 March 2010. 25 March 9, 2011 Page & Turnbull, Inc. -28- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California used for GATR, the Civil Engineering Supply was located in part of Building 119, the Civil Engineering Quarters (CEQ), also known as Station Support. When GATR moved to Mt. Thayer, the CEQ moved the supply portion into Building 110 until the new power plant (Building 112) was completed and the original power plant (Building 120) was converted to the D.E. warehouse/supply. Around 1965, Building 110 was converted for training new personnel.28 Figures 13 and 14. Exterior and interior of GATR (Building 110), prior to construction of a separate GATR site, ca. 1959-1960. (Source: http://www.radomes.org/museum/) The Operations Building (Building 100) was used to process information received from the radars (Figure 15). This included a Digital Data Processor, and an AN/FST-2B “computer” which was installed in 1961 for the SAGE automated control system.29 The AN/FST-2B accepted all data input from the search and height finder radars and processed them into readable data for the radar scopes. The AN/FST-2B required a large room in the Operations Building to house all the equipment, as well as an air-conditioning system specifically designed to cool the equipment. The AN/FST-2B was replaced in 1973 by advanced technology in the form of an AN/FYQ-47, which took up only a couple racks of equipment instead of an entire room.30 Building 100 also included a room for cryptography, where encrypted messages were sent and received from NORAD and the various Air Defense Sector “Direction Centers.” This room included crypto “typewriters” that were used to encode messages, but the process of decoding was manual.31 Email correspondence with Basim Jaber, 23 March 2010. Telephone interview with Basim Jaber regarding the former Almaden AFS, 2 March 2010. 30 Email communication with Basim Jaber, 23 March 2010. 31 Ibid. 28 29 March 9, 2011 Page & Turnbull, Inc. -29- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California Figure 15. Operations (Building 100), the AN/FPS-90 (Building 107) and the corner of Building 102, ca. 1969. (Source: http://www.radomes.org/museum/) After operating as a NORAD Ground Control Intercept site from 1958 to 1963, the 682nd Radar Squadron reverted to a Long Range Radar Squadron in April 1966. At that time, it became part of the 26th Air Division headquartered at the Adair AFS in Oregon, under the command of the 4th Air Force at Hamilton Air Force Base, California. On 1 July 1968, the Squadron was incorporated into the Backup Interceptor Control Center (BUIC) system, which provided backup capability in the event that a regional control center was destroyed. The squadron’s mission again reverted to a Long Range Radar in March 1969, and on 15 September 1969, the squadron fell under the operational control of the 26th Air Division NORAD Region, headquartered at Luke Air Force Base, Arizona.32 By the mid-1970s, a handout provided by the 682nd Radar Squadron stated its mission was to “equip, administer and train all assigned personnel to provide surveillance data, height information, and IFF/SIF responses to the Region Control Center at 26AD/NORAD Region. We also provide ground-to-air communications and data link with aircraft in our area of responsibility.” 33 In May 1962, following construction of the AN/FPS-24 tower, the Air Force acquired land on the neighboring peak of Mt. Thayer and moved the Ground-to-Air Transmitter-Receiver (GATR) so that the radar would not interfere with GATR’s radio frequency signals. The primary building erected on Mt. Thayer was the Communications Transmitter/Receiver building, also known as the GATR Building (Building 700). Initially it contained mostly the same equipment as that used when GATR was in Building 110, but with some improvements. Over the years, the communications equipment 32 33 682nd Radar Squadron, Welcome to 682nd Radar Squadron, Almaden AFS, California (n.d.; post-1976) 2. 682nd Radar Squadron, 3. March 9, 2011 Page & Turnbull, Inc. -30- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California grew to include transmitters, receivers, antennae, data links, and a Klystron tube. A power line connected the GATR site to the power plant at the Operations site. Telephone lines came from the phone company to the demarcation point in the TELCO Building, and then local wiring was distributed throughout the facility. Radar Operations used the GATR via the TELCO lines to communicate to intercept and patrol aircraft.34 Other enhancements to the GATR site on Mt. Thayer included below-surface water storage and septic tanks (Buildings 711, 712, and 713, which appear no longer extant), antenna arrays, and a small security sentry house (Building 715/722) down the road. The sentry house was installed at the gate in the summer of 1966, possibly as a result of heightened anti-war efforts for those opposing the Vietnam War.35 The tall wood poles for lower-frequency antennae were placed in a mesh arrangement and sent and received signals from intercept aircraft on patrol for intercept missions. Another type of antenna array was the FRT-49 (no longer extant), a high power data-link transceiver “horizontal ladder array” (Figure 16). It protruded out from the east and west sides of the east and west sides of Building 700 and had a peak output of 20,000 watts. The FRT-49 was coupled with the GKA-5 data link for sending data to intercept fighters for cockpit on-screen display information. When Almaden AFS was designated as a Semi-Automatic Ground Environment (SAGE) site between January 1961 and Feb 1974, a SAGE Direction Center could communicate to the site via secure telephone lines to Building 700 and were able to communicate with intercept fighters within the Almaden AFS GATR transmission range remotely.36 Figure 16. GATR (Building 700) with tall poles for lower-frequency antennae and shorter FRT-49 horizontal array visible, ca. 1964-1965. (Source: N. McKiethan via B. Jaber Archives) Email correspondence with Basim Jaber, 2 March 2011. Email correspondence with Basim Jaber, 4 March 2011. 36 Ibid. 34 35 March 9, 2011 Page & Turnbull, Inc. -31- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California Support Facilities and Residential Facilities The support buildings and residential facilities at the former Almaden AFS are located at the southwest end of the site. At its peak, Almaden AFS housed approximately 120 people including employees and their families, and counted eighty-four buildings and structures. On average, the facility employed approximately 30 stationed military personnel and 50 to 100 civilian personnel.37 To support the radar installation and residential cantonment, the station included basic support facilities for water and sewage, fire protection, administration, heating and refrigeration, and supply. It also catered to community needs with facilities for medical and dental care, postal services, a commissary and exchange, a chapel, and a barber shop. Recreational facilities included a bowling alley, pool and gymnasium. Nearly all of the non-residential support buildings and the barracks were pre-fabricated Butler buildings, while the apartment buildings for families were of wood-frame construction. The widespread use of Butler buildings at Almaden AFS appears to be a departure from other Air Force stations that were constructed earlier in the 1950s in California, such as Klamath AFS and Mill Valley AFS (both established in 1951). There, the barracks, administration buildings, mess halls, recreation facilities, and maintenance buildings were primarily of wood-frame construction and based on standardized designs by the Chicago-based architectural firm of Holabird, Root and Burgee.38 Administration was located in Building 207, the Orderly Building (Figure 17). It housed the commander’s office, the first sergeant, and others who handled business operations. In its earliest years, the Almaden AFS commander lived in the Bachelor Officers’ Quarters (Building 205, also known as the Visiting Airman Quarters or the Transient Lodging Facility). As the names suggest, this building was mostly used as temporary housing and included four hotel-style rooms, a bar and lounge. 37“Site Survey Summary Sheet for DERP-FUDS site No. J09CA099900: Almaden Air Force Station.” Corps FUDS. Website accessed on 4 March 2010 from: http://www.corpsfuds.org/reports/INPR/J09CA0999inpr.pdf 38 National Park Service, Western Region. Historic American Buildings Survey: Mill Valley Air Force Station, HABS No. CA-2615 (San Francisco, CA: National Park Service, 1995) 7. March 9, 2011 Page & Turnbull, Inc. -32- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California Figure 17. View east from the barracks buildings (no longer extant) to the Headquarters/Orderly Room (Building 207) and Bacherlor Officers’ Quarters (Building 205) on the hill, ca. 1959-60. (Source: http://www.radomes.org/museum/) Single male enlisted personnel were housed in six steel Butler barracks. In 1974, the commander condemned the old barracks buildings because they were leaking, moldy, and no longer habitable. Five of the six barracks buildings were purchased by the U.S. Forest Service and dismantled. Only their concrete footings remain today. Personnel without families moved to leased quarters off-base, and the remaining barracks building (Building 233) became the chapel/photo lab/ceramics building.39 The twenty-seven family housing units (Buildings 510 to 517) on site were completed in 1959 (Figures 18 and 19). Dependent children attended nearby schools in San Jose via a bus service. According to the architectural drawings, the apartment buildings were designed by the architecture and engineering firm of Porter, Urquhart, McCreary & O’Brien (PUMO). PUMO also designed the Catalina Heights Neighborhood for Oxnard Air Force Base in 1958 as part of the Capehart military housing program. The Capehart and Wherry programs were designed to ease military housing shortages in the 1950s by allowing private sponsors to build units on or adjacent to military installations. The apartments at the former Almaden AFS resemble other Capehart and Wherry projects, including the 1953 Baker Beach apartments at the Presidio of San Francisco. Though not designed by PUMO, the Baker Beach apartments feature wood-frame construction clad in stucco, aluminum-sash windows, and open stairwells with decorative wood lattice screens. It therefore seems a fair assumption that PUMO’s designs for the Almaden AFS apartments were influenced by other mass-produced military housing designs of the period. 39 Telephone interview with Basim Jaber, chronicler of the former Almaden AFS, 2 March 2010. March 9, 2011 Page & Turnbull, Inc. -33- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California The threat of wild fires meant that fire protection was an important aspect of living on the mountain. Fire hose houses were located throughout the site, including sixteen fire hose houses with 1 ½ inch and 2 ½ inch pre-connected fire houses in the Cantonment area. All of the surviving fire hose houses are marked with an interior stencil that reads “Built by 115 CET Wisconsin ANG,” which appears to indicate they were fabricated by the 115th Fighter Wing of the Wisconsin Air National Guard. In addition to the hose houses, the site had a 1,500 gallon water distributor.40 Figure 18. Cantonment, ca. 1969. (Source: http://www.radomes.org/museum/) Figure 19. Playground by apartments, ca. 1969. (Source: http://www.radomes.org/museum/) 40 682nd Radar Squadron, 7. March 9, 2011 Page & Turnbull, Inc. -34- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California Medical and dental services were located within Building 213 (Figure 209). Two medical technicians provided routine medical care, and a civilian contract doctor offered services one day a week by appointment. An Air Force dentist visited the station for a period of thirty days every three months to take care of military personnel. Dental care for dependents was provided by local dentists in the San Jose area. A fully equipped ambulance was available on station 24 hours a day for emergencies. Military patients requiring care beyond the capabilities of the station were transported to Moffett Naval Air Station Dispensary, Letterman Hospital in San Francisco, or to Travis Air Force Base Hospital.41 Figure 20. Dispensary (Building 213), ca. 1959-1960. (Source: http://www.radomes.org/museum/) Community services were supplied by Almaden AFS for personnel and residents. The Post Exchange was located in the recreation hall, Building 245. Although small in size, it carried most basic necessities and some popular items, such as cameras, radios, stereos, calculators, and a small selection of clothing. Almaden AFS had a branch commissary supported by Travis Air Force Base. The store maintained a supply of canned goods, dairy products, frozen foods, produce, and other foodstuffs. The commissary was open during the weekdays, but not on weekends. Recreational facilities consisted of a pool table, a half-court gymnasium (Building 245), weight room, ping pong tables, a foosball table, a nine-foot swimming pool with a diving board, and a two-lane bowling alley with automatic pin-setters (Building 217) (Figure 20). Building 245 also included a library. Hobby shops were located in Building 233, and included a Photo Lab and a Ceramic Shop. The “Top of the Rock” Consolidated Open Mess in Building 212 required club membership to attend squadron functions. 41 682nd Radar Squadron, 6. March 9, 2011 Page & Turnbull, Inc. -35- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California Figure 21. View east to the Orderly Building (Building 207) from the swimming pool, ca. 1959-1960. (Source: http://www.radomes.org/museum/) Closure Almaden AFS came under TAC jurisdiction in 1979, and the facility’s closing ceremony took place on 29 March 1980 with a final lowering of the flag.42 The official “inactivation” date was 30 June 1980.43 On 30 September 1980, a total of 18.42 acres of leased land was disposed of by terminating two leases (14.60 and 3.82 acres). The net remaining acreage was 48.02 fee acres, 43.72 easement acres, and 8.20 leasehold acres for a total of 99.94 acres of land. In June 1982, control of the property and improvements was transferred to the General Services Administration (GSA). On 21 April 1986, the GSA quitclaimed 91.696 acres of perpetual easements and fee acres to the Midpeninsula Regional Open Space District (MROSD). The remaining 8.20 acres of leaseholds were terminated at that time.44 Today the site is part of the Sierra Azul Open Space Preserve. It is not open to the public because of environmental hazards, including asbestos and lead-based paint. In addition, most of the buildings have deteriorated due to damage from the 1989 Loma Prieta earthquake, as well as ongoing vandalism and a significant amount of weather exposure which has damaged both the exteriors and interiors. Telephone interview with Basim Jaber, 2 March 2010. Email correspondence with Basim Jaber, 23 March 2010. 44 U.S. Army. 42 43 March 9, 2011 Page & Turnbull, Inc. -36- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California OTHER NORAD RADAR FACILITIES IN CALIFORNIA The Almaden Air Force Station was one of two hundred air defense and long-range radar facilities that monitored the skies over the continental U.S. As such, it was one of about 23 Lashup (temporary) and permanent radar stations in California that were constructed to protect the West Coast from Soviet attack. The radar ranges generally reached up to 200 miles, though a couple, like Almaden’s AN/FPS-24, reached 250 miles. The ranges overlapped for good coverage, and removable radars were positioned in gaps. In order to provide a comparative basis for the facilities at the former Almaden AFS, the following is a discussion of the other nine permanent NORAD radar facilities in California (Air Force Stations— excluding impermanent Lashup sites and Air Force Bases). It includes information about when the installations were established, what types of radar equipment were operated, when the stations closed, and any available information about their current state. Mill Valley Air Force Station The closest station north of Mt. Umunhum was the Mill Valley Air Force Station, located on a 106.4 acre site on the west peak of Mt. Tamalpais (Figure 22). The site was leased from the Marin Municipal Water District in 1942 and returned to them in 2005. The 666th Aircraft Control and Warning (AC&W) Squadron began operating an AN/CPS-6B radar there in late 1951. Mill Valley AFS was designated the Master Direction Center under the manual control system of operations in 1951, meaning that it had operational tactical control over three other Ground Radar Squadrons, two Navy picket ships, two Air Early Warning and Control Aircraft, sixteen Army Air Defense Artillery Nike-Ajax and Nike-Hercules units in the San Francisco-Travis Air Force Base complex.45 Between 1955 and 1964, the Mill Valley AFS operated an AN/FPS-8, AN/GPS-3, AN/FPS-4 height-finder radar, AN/FPS-6 set, AN/FPS-7 search radar, AN/FPS-6B height-finder radar, AN/FPS-26A height-finder radar, and AN/FPS-90. In January 1961, the site began feeding data into the SAGE System. Following the station’s integration into the SAGE system, Battery Integration and Radar Display Equipment (BIRDIE) was installed in April “to provide a tightly-knit control of Nike defenses, unattainable prior to its development, assuring optimum target engagement in the most efficient and economical manner.” At this time, Mill Valley AFS was designated the headquarters for the San Francisco NORAD Control Center, composed of both Army and Air Force personnel and equipment. The same year, the 666th squadron became host to the 40th Artillery Brigade Air Defense Command Post, and was put in charge of the Nike-Hercules missile systems in the San Francisco45 National Park Service, Western Region. Historic American Buildings Survey: Mill Valley Air Force Station, HABS No. CA-2615 (San Francisco, CA: National Park Service, 1995) 8. March 9, 2011 Page & Turnbull, Inc. -37- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California Travis AFB area.46 In 1966, the AN/FPS-26A was removed from SAGE duties when it was converted to an AN/FSS-7 SLBM detection & warning radar. The U.S. Army Air Defense Command Post also shared this radar site during the 1960s for Nike-missile control because the site was linked with the Nike missile site at nearby Fort Barry.47 Figure 22. Former Mill Valley Air Force Station, 2010. FAA facility to the right, remaining foundations of other buildings to the left. (Source: Google Maps, 2010) Mill Valley AFS came under Tactical Air Command (TAC) jurisdiction in October 1979. During the 1980s, most of the property was turned over to the National Park Service and the Federal Aviation Administration (FAA). The Air Force retained control of the height-finder radar (modified to an AN/FPS-116) and the SLBM radar, which was deactivated circa 1980. In 1995 the FAA operated an AN/FPS-66A search set, which was replaced in the late 1990s with an ARSR-4. At its height, the Air Force Station contained sixty-two buildings, and radar systems were housed in radome tower buildings. Most of the radar facilities were deactivated by 1980, but the ARSR-4 continues to function for the FAA.48 The majority of facilities have since been removed. The site was documented in the Historic American Buildings Survey (HABS) in 1995, and was determined eligible for listing in the National Register of Historic Places based on its significant role as one of the most important radar stations in the country. According to the HABS documentation: National Park Service: 9. Ibid. 48 “Mt. Tamalpais West Peak/Mill Valley AFS,” Website accessed on 9 March 2010 from: http://wikimapia.org/1482223/Mt-Tamalpais-West-Peak-Mill-Valley-AFS-site; and “Mill Valley AFS,” Website accessed on 9 March 2010 from: http://www.militarymuseum.org/MillValleyAFS.html. 46 47 March 9, 2011 Page & Turnbull, Inc. -38- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California At every phase of its history—as a control station in the 1950s, as a SAGE combat division center from 1961 to 1963, as San Francisco Defense Area NORAD Control Center from 1961 to 1974, and as one of six SLBM radar stations from 1968 to 1980— it was one of the few radar stations to hold a position of leadership.49 Because it was determined eligible for listing on the National Register, the Mill Valley Air Force Station was automatically listed on the California Register of Historical Resources. It was assigned a California Historic Resource Status Code of “2D2,” which means “Contributor to a district determined eligible for NR by consensus through Section 106 process. Listed in the CR.” Point Arena Air Force Station Further north along the coast, the Point Arena AFS operated from December 1951 to the mid1980s. The 72-acre station was manned by the 776th Radar Squadron until the unit was deactivated in 1980, and an element of the 26th Air Defense Squadron continued operations. The site included barracks, a post exchange, recreation center, tennis courts and a pool, wastewater treatment plant, boiler plant, and an operations building, among other structures.50 It featured two radar towers, including an eighty-foot concrete tower, much like the one at the Almaden AFS. The Point Arena AN/FPS-24 general surveillance radar was the first of twelve productions (Almaden’s was the second) (Figure 23). During its operational years, the site contained an AN/TPS-1B radar, AN/FPS-3 and AN/FPS-4, AN/FPS-8, AN-GPS-3, AN-FPS-20 and AN/FPS-6 set, AN-FPS-6B, AN-FPS-24, AN-FPS-26A and AN-FPS-90 height-finders, AN/FPS-93A, AN-FPS-91A and AN/FPS-116. In addition to the site’s radars, it also supplied ground-to-air (GATR) communications to aircraft in the operating area. The GATR site was remotely located from the radar site to minimize interference from the radars into the radio gear.51 Nearly identical to GATR at Almaden AFS, the Point Arena GATR featured tall poles for lower-frequency antennae and a linear FRT-49 antenna array (Figure 24). National Park Service: 10. “April 2004 SitRep,” Air Defense Radar Museum. Website accessed on 11 March 2010 from: http://www.radomes.org/museum/ 51 “Point Arena Air Force Station. Wikipedia. Website accessed on 9 March 2010 from; http://en.wikipedia.org/wiki/Point_Arena_Air_Force_Station 49 50 March 9, 2011 Page & Turnbull, Inc. -39- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California Figure 23. Point Arena AFS, AN/FPS-24 tower. (Source: http://www.uneeda-audio.com/776th/) Figure 24. Aerial of the GATR site at Point Arena AFS (n.d.) (Source: http://www.radomes.org/museum/) Point Arena AFS came into NORAD’s SAGE command and control system in 1960. The site came under TAC jurisdiction in 1979. Once manned by 200 Air Force personnel, by 1982 Point Arena AFS was operated by forty-four civilians. The site remained in use as joint FAA and civilian-manned radar station until 1998, but is now closed.52 52 Ibid. March 9, 2011 Page & Turnbull, Inc. -40- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California Klamath Air Force Station Klamath AFS was first established in 1951 as a temporary installation, but became part of the permanent radar network in April 1952 when the 777th AC&W Squadron began operating AN/FPS3 and AN/FPS-4 radars. Between 1956 and 1966, the facility operated an AN/GPS-3, AN/FPS-20, AN/FPS-6, AN/FPS-6A, AN/FPS-20A, AN/FPS-66, AN/FPS-90, AN/FPS-26 height-finder, and an AN/FPS-27 long-range search radar. The 777th became a SAGE radar squadron in 1960, and the site came under TAC jurisdiction beginning in 1979. In the 1980s, much of the property was turned over to the National Park Service, and the operations area became an FAA/U.S. Air Force joint-use facility. In 1995, the FAA operated an AN/FPS-66A search set in the old AN/FPS-27 tower. The Klamath AFS has since been replaced by the FAA/U.S. Air Force site at Rainbow Ridge, CA.53 Red Bluff Air Force Station Red Bluff AFS began in 1955 with the acquisition of 24.2 acres of grazing land south of Redding in Tehama County (Figure 25). The station became operational by the end of 1956 with the 85th AC&W Squadron as a garrisoning unit. The 858th initially operated the AN/MPS-8 height finder radar and the AN/MPS-11 search radar, which were both mobile systems. At different times between 1959 and 1970, the facility operated fixed AN/FPS-6, AN/FPS-6A, AN/FPS-67 fixed search radar, AN/FPS-90 height finder radar. The radar information began being fed into the SAGE command and control system in 1960, which removed the Ground Control Intercept function from the station and reduced its manpower requirements. A GATR site and two gap filler annexes were established in 1960. With the transfer of the GATR function, the former on-site building was converted into the station’s commissary. In 1964, Red Bluff AFS came under joint control of the FAA and the ADC. The 859th Squadron was inactivated in 1970, and the facility closed. In 1971, the GATR site and operations portion of the main station were transferred to the FAA, who continues to operate a search radar there as part of the Joint Surveillance System (JSS), a joint U.S. Air Force/FAA air sovereignty monitoring system. By the end of 1972, the remainder of the station was transferred to Tehama County, which developed the site into a county park. 53 “Klamath Air Force Station,” Wikimapia. Website accessed on 15 March 2010 from: http://wikimapia.org/5166808/Klamath-Air-Force-Station March 9, 2011 Page & Turnbull, Inc. -41- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California Figure 25. Red Bluff Air Force Station, date unknown. (Source: http://www.radomes.org/museum/) Red Bluff AFS was unique to California radar stations in that it was the only station that used metal buildings for administration, logistical support, and housing. All of the other stations used wood frame construction for at least some of their buildings. With closure of the station, most of the buildings were disassembled and transferred to government agencies and non-profit organizations.54 Madera Air Force Station Several radar Air Force Stations were situated south of Almaden. The Madera AFS was located northeast of Fresno, and was established as a temporary emergency site. It was first occupied by the 774th AC&W Squadron in 1951, and construction began that year on several concrete and woodframe buildings to house the radar and support equipment, as well as its eight officers and 108 enlisted airmen and noncommissioned officers. The site became a permanent Air Force Station in 1952 (Figure 26). Nine family housing units were constructed in 1956, and seventeen more in 1960. The facilities at Madera AFS also included a swimming pool, skeet range, athletic court and field, base exchange, and a three-hole golf course, which contributed to the station’s unofficial nickname, “Country Club of the Air Force.”55 54 “Red Bluff Air Force Station,” The California State Military Museum, Website accessed on 15 March 2010 from: http://www.militarymuseum.org/RedBluffAFS.html. 55 “Madera Air Force Station,” The California State Military Museum, Website accessed on 9 March 2010 from: http://www.militarymuseum.org/Madera%20AFS.html. March 9, 2011 Page & Turnbull, Inc. -42- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California Figure 26. Aerial of former Madera Air Force Station, 2010. (Source: Google Maps, 2010) Madera AFS was integrated into NORAD’s SAGE command and control system in 1960. With this change, the 774th AC&W Squadron became the 774th Radar Squadron (SAGE). Between 1950 and 1963, the site operated an AN/TPS-1B search radar, AN/FPS-3 and height finder, AN/FPS-4 radar sets, an AN/FPS-6A height finder radar set, an AN/FPS-20 system, an AN/FPS-66 and an AN/FPS-90.56 On 25 June 1966, the Madera AFS and the 774th Radar Squadron were both deactivated. In December of that year, the U.S. Air Force issued a permit to the Bureau of Indian Affairs (BIA), Department of the Interior to use the site as a school and vocational training center.57 It is unclear if any buildings remain standing at the site. Cambria Air Force Station The Cambria AFS was established in 1951 on the Pacific coast, about thirty miles north of San Luis Obispo. The 34-acre site contained an AN/FPS-26A height finder, as well as AN/FPS-6 and ANFPS-107 radar towers during its period of operation (Figure 27). The radar units have since been dismantled, but the structures remain (Figure 28 and 29). 56 57 Ibid. Ibid. March 9, 2011 Page & Turnbull, Inc. -43- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California Figure 27. Former Cambria Air Force Station, n.d. (ca. 2000) (Source: http://www.radomes.org/museum/recent/CambriaAFSCA.html) The AFS was nearly self-sufficient, and included a post exchange, library, mess hall, theater/bowling alley, tennis courts, dark room, medical unit, two radar towers, six barracks, a bomb shelter, a telephone exchange building, officers’ quarters, a pump house, automotive maintenance facility, two gate houses, a boiler room, a sewage treatment plant, a water filtration facility, power plant building, club/pool room, commissary, recreation building, administration building, operations buildings, maintenance shop, and various ancillary buildings (Figure 30).58 By 1968, 180 Air Force personnel and twenty-five civilian workers were employed at Cambria AFS. About sixty percent of the staff lived off-station, some in an Air Force housing tract in Cambria, some in Cayucos, and others in Morro Bay.59 The AFS was closed in 1979. As of 2008, the site was owned by a private individual, but it was still in minor use by the government to broadcast safety notices and weather information to ships through USCG Navigational Telex. 58 “Cambria Air Force Radar Station Conversion Project Proposal,” Website accessed on 9 March 2010 from: http://www.macronet.org/airbase/airforce.html 59 http://sloblogs.thetribunenews.com/slovault/2008/04/13/1968-cambria-air-station/ March 9, 2011 Page & Turnbull, Inc. -44- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California Figures 28 and 29. Former Cambria AFS—the AN/FPS-26A radome in 1968, and the AN/FPS-107 radar tower in 2004. (Source: http://sloblogs.thetribunenews.com/slovault/2008/04/13/1968-cambria-air-station/; http://www.radomes.org/museum/recent/CambriaAFSCA.html) Figure 30. Former Cambria AFS barracks in the cantonment area, July 2003. (Source : http://www.radomes.org/museum/recent/CambriaAFSCA.html) Santa Rosa Island and Lompoc Air Force Stations The Santa Rosa Island AFS operated from 1952 to March 1963 on Santa Rosa, one of the Channel Islands. At various times, the 669th AC&W Squadron operated an AN/CPS-6B, AN-FPS-10, AN/FPS-3, AN-GPS/3, and AN/MPS-14. The Lompoc AFS was established at Oak Mountain in Santa Barbara County in 1963, when the 669th AC&W Squadron moved from Santa Rosa Island AFS (Figure 31). The 669th operated as part of the SAGE network, and was administered by Vandenberg Air Force Base. A GATR facility was located about a mile south at Sudden Ranch. Between 1963 and 1968, the Lompoc AFS operated an AN/FPS-67, AN/FPS-6, AN-FPS/6A height-finder radar, and AN-FPS-67. The 669th was deactivated in June 1968. The GATR site has been retained.60 60 “Lompoc Air Force Station,” Website accessed on 15 March 2010 from: www.radomes.org March 9, 2011 Page & Turnbull, Inc. -45- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California Figure 31. Lompoc AFS, ca. 1964. (Source: http://www.radomes.org/museum/) Boron Air Force Station Boron AFS was established in February 1952 in the Mojave Desert, and was initially managed by Edwards Air Force Base (Figure 32). The 750th AC&W Squadron subsequently assumed command of the site and operated two AN/FPS-10 radars, one of which remained until 1959. Between 1958 and 1969, Boron AFS operated an AN/FPS-6 height-finder radar, AN/FPS-61 height-finder, ANFPS-10, AN/FPS-20, AN/FPS-35 FD, AN/FPS-26A and AN/FPS-90 height-finder radars, and an AN/FPS-67 with a radome. The facility provided data for the regional SAGE center in 1961, and the AN/FPS-6A became an operational ADC/FAA joint-use radar. The 750th was deactivated in June 1975. Part of the site continued to be used by the FAA, while the other section was used as a federal prison camp, which subsequently closed in April 2000.61 61 “Boron Federal Prison Camp/Boron AFS,” Wikimapia. Website accessed on 15 March 2010 from: http://wikimapia.org/3945077/Boron-Federal-Prison-Camp-Boron-AFS-site March 9, 2011 Page & Turnbull, Inc. -46- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California Figure 32. Aerial of former Boron Air Force Station, 2010. (Source: Google Maps, 2010) San Clemente Air Force Station and San Pedro Hill Air Force Station/Fort MacArthur The 670th AC&W Squadron began operations at San Clemente AFS in May 1952 with a single AN/FPS-3 radar. A year later, an AN/FPS-4 height-finder radar joined the site. Over the years between 1955 and 1960, the facility also operated an AN/FPS-8, AN/GPS-3, and AN/FPS-4. The site was deactivated in 1960, and the 670th AC&W Squadron relocated to Fort MacArthur/San Pedro Hill AFS, a joint-use Air Force/Army/FAA radar site. San Clemente Island was handed over to the Navy. Operations at San Pedro Hill AFS/Fort MacArthur included AN/FPS-6B and AN/FPS-26A height-finder sets in 1963, and AN/FPS-90 and AN/FPS-27 radars in 1964. The 670th Radar Squadron was deactivated in April 1976 (Figures 33 and 34). Figures 33 and 34. San Clemente AFS- radar in 1958; the site in recent years. (Source: http://www.radomes.org/museum/) March 9, 2011 Page & Turnbull, Inc. -47- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California Mt. Laguna Air Force Station Operations at the Mt. Laguna Air Force Station, located east of San Diego, began in April 1952 (Figures 35 and 36). At that time, the 751st AC&W Squadron (later 751st Radar Squadron) operated AN/CPS-4 and AN/FPS-3 radars. Between 1952 and 1966, the Radar Squadron also operated an AN/FPS-8, AN/GPS-3, AN/FPS-6, AN/FPS-7C search radar and AN/FPS-6 and 6B height-finder radars, AN/FPS-90 set; AN/FPS-26A FD height-finder radar; and AN/FSS-7 SLBM D&W radar. The site became integrated into the SAGE system in 1961. Mt. Laguna became a joint-use ADC/FAA facility around 1965. In 1979 the facility came under TAC jurisdiction. In the 1980s, the FAA assumed greater control, replacing the AN/FPS-7E with an ARSR-3 search radar, leaving the Air Force responsible only for the height-finder tower, which was removed circa 1988. In the late 1990s, the ARSR-3 was replaced by the ARSR-4.62 The other radars have since been removed, and only the towers remain. The FAA currently uses the ARSR-4 radar for en route flight safety and air traffic control. The site is scheduled to be dismantled in 2010 by the U.S. Forest Service with federal stimulus funds.63 Figures 35 and 36. Former Mt. Laguna AFS, married enlisted quarters, ca. 1994 and the AN/FPS-26 height-finder radar/AN-FSS-7 SLBM radar tower with the FAA’s ARSR-4 radar behind, 2009. (Source: http://www.radomes.org/museum/recent/MountLagunaAFSCA.html) 62 “Mount Laguna AFS,” Website accessed on 9 March 2010 from: http://wikimapia.org/5329703/Mount-Laguna-AFSsite 63 “751st Radar Sqdn., Mount Laguna AFS, CA,” Website accessed on 9 March 2010 from: http://www.radomes.org/museum/recent/MountLagunaAFSCA.html March 9, 2011 Page & Turnbull, Inc. -48- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California V. EVALUATION OF THE FORMER ALMADEN AIR FORCE STATION AS A POTENTIAL HISTORIC DISTRICT The following is an evaluation of the former Almaden AFS for its potential eligibility as a historic district. The evaluation uses the significance criteria of the California Register of Historical Resources and the National Register of Historic Places, as well as integrity considerations that were previously discussed at length in the Methodology section. Individual evaluations are located in VI. Inventory and Brief Evaluation of Individual Buildings. Criterion A/1 (Events) The former Almaden Air Force Station does not appear eligible for listing in the National Register under Criterion A or the California Register under Criterion 1 (Events) as a potential historic district. Though the facility was constructed as part of NORAD’s Cold War defense system for the United States and Canada, nine permanent Early Warning Radar Air Force Stations existed in California during the same period. The radars at the Almaden AFS overlapped in range with the nearby stations, and all of the radars worked in concert to detect foreign objects in airspace along the Pacific Coast. Likewise, all these facilities were connected to the SAGE command and control system in 1960-61, and at least three other stations contained separate GATR facilities. Thus, the former Almaden AFS does not appear singularly significant in function, nor was its equipment unique. The facilities and operational tasks for each radar station were quite similar, and the hierarchy of command was nearly identical—aside from those stations which served as a command post or headquarters. For example, Mill Valley AFS functioned as a control station in the 1950s, as a SAGE combat division center from 1961 to 1963, as San Francisco Defense Area NORAD Control Center from 1961 to 1974, and as one of six SLBM radar stations from 1968 to 1980. Because of these significant functions, the station was determined eligible for listing as a historic district on the National Register in 1995, which meant that it was automatically listed in the California Register as well. By contrast, the former Almaden AFS does not rise to the same level of significance as Mill Valley AFS, and thus does not appear eligible for listing on the California Register or National Register. Almaden AFS operated from 1958 to 1980. It was the not the first Cold War-era Air Force radar station to be established in California. In fact, it was the last station established without transferring a radar squadron from a previous location in California (i.e. Santa Rosa AFS to Lompoc AFS and San Clemente AFS to Fort MacArthur). The Mill Valley, Point Arena, Klamath, and Cambria Air Force Stations were established in 1951, and Madera, Santa Rosa, Boron, San Clemente, and Mt. Laguna March 9, 2011 Page & Turnbull, Inc. -49- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California Air Force Stations were established in 1952. The establishment of these stations may be considered more significant than Almaden AFS because the 1951-52 system of Early Warning Radar stations was the United States’ first major construction project as a result of Cold War hostilities.64 Other stations also operated for longer periods than Almaden AFS, including Klamath AFS which closed in the 1980s, Mt. Laguna which closed in the 1990s, and Point Arena which did not close until 1998. In conclusion, the former Almaden AFS does not stand out as particularly significant compared with other Cold War-era Air Force radar stations in California, such as those which served as local or regional command centers. It therefore does not appear eligible for listing as a historic district on the National Register or the California Register. Criterion B/2 (Persons) The former Almaden Air Force Station does not appear eligible for listing in the National Register under Criterion B or the California Register under Criterion 2 (Persons). It was a military facility and by definition all of the personnel worked together in support of the operational mission. Research has failed to turn up an intimate association with a particularly prominent person or persons that would justify its inclusion in the National Register or California Register under this criterion. Criterion C/3 (Architecture & Design) The former Almaden Air Force Station does not appear eligible for listing in the National Register under Criterion C or the California Register under Criterion 3 (Architecture & Design) as a potential historic district. The buildings at the former Almaden AFS are common amongst radar stations of the Cold War era in terms of construction materials, style, size, massing, and use. Prefabricated steel Butler buildings were most often used for radar support, administration, community services, and airmen barracks. All of the stations except Red Bluff AFS used wood-frame construction for apartments or other buildings, in addition to the use of steel buildings. The wood-frame apartments, though modern in design, resemble other mass-produced military housing of the era, such as those constructed for the Capehart and Wherry programs. The buildings likewise do not appear significant in the portfolio of Porter, Urquhart, McCreary & O’Brien, who worked on larger military housing projects elsewhere. The radar structures used at the Almaden AFS were not unique, but rather, followed common conventions similar to other radar installations. Height-finder radars were placed on steel structural supports, while search radars were placed on multi-story concrete cubes. The specific types of radars varied from station to station, and also varied over the years as technology improved. However, a 64 National Park Service: 1. March 9, 2011 Page & Turnbull, Inc. -50- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California select number of radars were in use during a given time period. For example, all nine other stations in California used AN/FPS-6 series height-finder radars, and seven used the AN/FPS-90. Three used the AN/FPS-20 search radar, and Santa Rosa AFS used the AN/MPS-14. Point Arena was the only other Early Warning Radar Station in California to operate the large AN/FPS-24. Though the concrete tower at the former Almaden AFS is distinctive, it supported the second of twelve production models of the AN/FPS-24—the first being at Point Arena. Furthermore, the radars themselves have been removed from the towers at the former Almaden AFS. Based upon Page & Turnbull’s methodology of highly technical and scientific resources, which emphasizes the need to retain some technical equipment related to the historic function of the building, the towers consequently do not retain integrity of workmanship and association. Thus, the historic integrity has been lost. A rare fully intact AN-FPS-24 (the radar sail remains) is located at Camp Hero on Long Island, New York. The buildings and structures at the former Almaden AFS do not represent the work of a master or possess high artistic value. They embody the characteristics of a type, period, and method of construction, but within the broader historic context of the period, they do not stand out as a collection of buildings that should be recognized for their design as a National Register or California Register Historic District. Finally, the facility’s site and layout are not unique compared to the other Cold War-era Air Force radar stations. For example, the Mill Valley, Point Arena, Klamath, Cambria, Santa Rosa Island, San Clemente, and Mt. Laguna Air Force Stations were all situated on elevated pieces of land—either mountains or coastal bluffs—as these locations were advantageous for non-obstructed radar placement. It was also not uncommon for stations to combine the radar installation with multiple family housing and community services because the facilities were situated in relatively isolated locations. Criterion D/4 (Information Potential) The analysis of the former Almaden Air Force Station for eligibility under California Register, Criterion 4 (Information Potential), which is typically reserved for archaeological resources, is beyond the scope of this report. However, the site will likely not have merit under this criterion from its era as an Air Force Station. Evaluation Conclusion Though the entire site as a whole does not appear to possess the level of significance required for listing on the National Register or the California Register, there are layers of importance within the March 9, 2011 Page & Turnbull, Inc. -51- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California site. The area most relevant to the historic purpose and function of the Air Force Station was the radar facility at the top of Mt. Umunhum. The cluster consisting of Operations (Building 100), the concrete tower for the AN/FPS-24 (Building 102), the steel structure for the AN/MPS-14 (Building 108), and the steel Butler building (Building 110) together represent the most important function of the site. They also exemplify typical construction methods. Though the buildings and structures lack the historic integrity needed to qualify for eligibility as a small historic district on the California Register, they do offer an excellent opportunity for historic interpretation of the site (see VIII. Recommendations). March 9, 2011 Page & Turnbull, Inc. -52- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California VI. INVENTORY & BRIEF EVALUATION OF INDIVIDUAL BUILDINGS This section includes summary information for each of the individual surveyed buildings, including the location, date of construction, function, brief description/historic context, and a brief evaluation utilizing the National Register and California Register criteria and assessment of integrity. The buildings are generally separated into the following uses: Special Military Purpose (radar operation), Support (functional support to the radars and operation of the station as a whole), Residential (housing), and Ancillary (sheds, outbuildings, etc.). The majority of the historic background information was provided by local Santa Clara County resident Basim Jaber.65 Regarding historic integrity, to reiterate, most of the buildings at the former Almaden AFS show deterioration due to weathering and neglect. However, it is important to note that historic integrity is not synonymous with condition. A building or structure can possess all or many of the seven aspects of integrity, even if the condition of the materials has degraded. Condition becomes a more important factor when weathering or vandalism has led to the outright loss of historic materials, such that the resource can no longer convey a direct connection to its historic function and design. 65 Email correspondence with Basim Jaber, 9 March 2010. March 9, 2011 Page & Turnbull, Inc. -53- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California 100: Operations Date of Construction: 1957; addition 1959 Property Type: Special Military Use- Radar Operations Historic Context Notes: Originally constructed as two separate buildings of steel and concrete block construction, a third section of concrete block was built in 1959. The roof was joined to make one building with three separate sections inside for scopes, cryptography, and administration. Cryptography was later moved to the main FPS-24 radar tower. Radiation shielding was added in 1963. Evaluation: The building is not of significant design or construction. Its function was important within the station as the control arm of the radar facility. Thus, the building possesses significance under Criterion A/1, but it is not individually eligible for the National Register or California Register due to lack of integrity. Retains Integrity: No (Lacks integrity of setting since the radar towers that once immediately surrounded it are no longer extant. Lacks integrity of workmanship, feeling and association since the equipment inside has been removed and it no longer functions in any capacity related to its original use.) March 9, 2011 Page & Turnbull, Inc. -54- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California 102: Radar Tower FPS-24 Date of Construction: 1959-1961 Property Type: Special Military Use- Concrete Radar Support Tower Historic Context Notes: The 19,845 square foot, five-story, cast-in-place concrete building was constructed from 1959 to 1961, and the radar it supported on its roof was fully operational in 1962. The AN/FPS-24 search radar was the second of twelve production models (the first was located at Point Arena, whose tower has recently been restored). The radar had a range of 250 miles, whereas most radars had a range up to 200 miles. The radar was removed from the tower in June 1980. Evaluation: Significant to former Almaden AFS under Criterion A/1 (Events) as the most prominent and directly-related example of radar operation at the site, and Criterion C/3 (Architecture/Design) as the only concrete radar tower at the site which was built for one of the most high-powered antennas in California. However, it is not individually eligible for the National Register or California Register due to lack of integrity. Retains Integrity: No (Lacks integrity of materials, workmanship, and association, largely because the radar unit on the roof and the other technical machinery to operate the radar has been removed. The removal of the radar and equipment prevents the building from directly conveying a connection to its historic function and design.) March 9, 2011 Page & Turnbull, Inc. -55- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California 105: Fallout Shelter Date of Construction: 1961 Property Type: Support- Fallout Shelter Historic Context Notes: The 1,590 square foot fallout shelter consists of two Quonset huts placed longitudinally adjacent to one another, rock-lined, and lead painted. An escape hatch and a concrete staircase next to Building 100 access it from above. Never needed, and used as storage. Evaluation: Not individually eligible for the National Register or California Register because design and construction is typical and the fallout shelter was never used as such. Retains Integrity: Yes March 9, 2011 Page & Turnbull, Inc. -56- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California 108: Radar Tower MPS-14 Date of Construction: 1962 Property Type: Special Military Use- Steel Radar Support Tower Historic Context Notes: This mobile heightfinder radar was the last radar constructed at the site. The footings of the tower measure 19 feet by 19 feet, and the building is approx. 40 feet tall to the platform. The radar was removed from the steel tower in the spring/summer of 1980. Evaluation: Significant within the former Almaden AFS under Criterion A/1 (Events) and Criterion 3/C (Architecture/Design) as the only steel height-finder radar tower remaining on site. Aside from Building 102, it is the other structure to directly relate to the station’s radar defense mission. However, it is not individually eligible for the National Register or California Register due to lack of integrity. Retains Integrity: No (Lacks integrity of materials, workmanship, and association and association, largely because the radar has been removed. The removal of the radar and associated equipment prevents the building from directly conveying a connection to its historic function and design). March 9, 2011 Page & Turnbull, Inc. -57- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California 110: Training Date of Construction: 1957 Property Type: Special Military Use - GATR, Storage, Training Historic Context Notes: The 1,080 square foot building was constructed as the original Ground to Air Transmitter Receiver (GATR) communications building. GATR moved to Mt. Thayer in 1962 and this building became the D.E. (civil engineering) warehouse before it was converted to personnel training in 1965. Evaluation: Significant within the site under Criterion A/1 (Events) as the first GATR building. Not eligible as an individual resource on the National Register or California Register due to lack of historic integrity. Retains Integrity: No (Lacks integrity of workmanship, feeling, and association because the GATR equipment and function was removed in 1962. Without the equipment, the shell of the building does not convey the connection to this historic use, and the building resembles all other steel Butler buildings, which were used in a variety of ways.) March 9, 2011 Page & Turnbull, Inc. -58- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California 112: Electrical Power Station Date of Construction: 1960 Property Type: Support Facility—power station Historic Context Notes: The 5,660 square foot building was constructed with a steel frame, concrete masonry unit (CMU) and cementasbestos board siding, and a steel roof. It was not the original power plant at the site. Consists of four Nordberg model #90180634 Diesel engines rated at 933 hp each. This power plant was constructed to support the new AN/FPS-24 radar built in 19591962. Three of the generators ran in excess of 73,000 hours, and the fourth developed problems after 1500 hours and was then used for parts for the other machines. Evaluation: This building supported the function of the radars, and is not individually significant. Retains Integrity: Yes 114: Sheet, Pipe & Paint Storage Date of Construction: 1965 Property Type: Ancillary— storage Historic Context Notes: N/A Evaluation: Support facility, and not individually significant. Also, not age-eligible because it is less than fifty years old. Retains Integrity: No (Lacks integrity of design, materials, workmanship, feeling, and association.) March 9, 2011 Page & Turnbull, Inc. -59- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California 115: Security Sentry House Date of Construction: 1964 Property Type: Support Facility—security Historic Context Notes: The 215 square foot corrugated metal building at the entrance to the operations area at the top of the mountain. The building may have originally been located at the main gate on Mt. Umunhum Road in 1964, and moved to the operations area shortly thereafter. Evaluation: Support facility, and not individually eligible for the National Register or California Register. Also, not age-eligible because it is less than fifty years old. Retains Integrity: Yes 118: Diesel Fuel Pump Date of Construction: 1957 Property Type: Support Facility—pump house Historic Context Notes: 250 square foot, concrete block building. Two 80,000-gallon diesel DF2 tanks were located below, as well as a spill containment earthen dam. This was the site of heavy soil contaminants that were recently abated by the Army Corps of Engineers. Evaluation: Support facility, and not individually eligible for the National Register or California Register. Retains Integrity: Yes March 9, 2011 Page & Turnbull, Inc. -60- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California 119: CE Maintenance Shop Date of Construction: 1957 Property Type: Support Facility—Maintenance Historic Context Notes: The 1,920 square foot building was also known as the Civil Engineering Quarters (CEQ). It was constructed with a pre-fabricated steel structure and skin manufactured by the Butler Manufacturing Co. Evaluation: Support facility, and not individually eligible for the National Register or California Register Retains Integrity: Yes March 9, 2011 Page & Turnbull, Inc. -61- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California 120: Warehouse Supply & Equipment Date of Construction: 1957 Property Type: Support Facility— power plant, warehouse Historic Context Notes: This 2,190 square foot building was the original power plant used to power the AN/FPS-20 search radar and height finder sets. It contained three or four Cummins Turbo-diesel generators. The generators were removed in 1962 when the AN/FPS-20 was decommissioned and removed. The building was converted to supply room at that time. Evaluation: Support facility, and not individually eligible for the National Register or California Register Retains Integrity: No (Lacks integrity of materials, workmanship, and association due to the change from its original purpose and missing materials.) 200: Water Pump Station Date of Construction: 1957 Property Type: Support Facility—pump station Historic Context Notes: The 240 square foot, corrugated metal building was used to pump water from the “upper” and “lower” pump houses on the final route to the water tanks. Also used for pressurization of fire hydrants on station. Evaluation: Support facility and not individually eligible for the National Register or California Register Retains Integrity: Yes March 9, 2011 Page & Turnbull, Inc. -62- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California 205: Bachelor Officers’ Quarters Date of Construction: 1957 Property Type: Support Facility- temporary lodging Historic Context Notes: 1,920 square foot steel Butler building was also known as the Visiting Airman Quarters (VAQ), the Transient Lodging Facility (TLF), and the Bachelor Airman Quarters (BAQ). Evaluation: Support facility, and not individually eligible for the National Register or California Register. Retains Integrity: Yes 206: Fire Hose House Date of Construction: ca. 1957 Property Type: Ancillary—fire protection Historic Context Notes: All fire hose houses were built between 1957 - 1958. The hydrants were installed first, then these structures were built to shelter the hoses. All of the hose houses were in place before the station became operational in 1958, and all show the interior stencil “Built by 115 CET Wisconsin ANG.” Evaluation: Not individually eligible for the National Register or California Register Retains Integrity: No (Lacks integrity of materials and workmanship because some of the walls and the doors are missing) March 9, 2011 Page & Turnbull, Inc. -63- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California 207: Squadron Headquarters Orderly Room Date of Construction: 1957 Property Type: Support Building- headquarters Historic Context Notes: The 1,920 square foot pre-fabricated steel Butler building housed administrative functions. It included the Commander's Office, admin assistant to the Commander, personnel office, mail room, etc. Evaluation: This building functioned in the daily operation of the station, but was not a part of any significant events, nor is its architecture distinctive. It is not individually eligible for the National Register or California Register. Retains Integrity: Yes 211: Auto Maintenance Shop, aka Motor Pool Date of Construction: 1960 Property Type: Support Facility— auto shop Historic Context Notes: This is a 1,984 squarefoot pre-engineered metal building. Evaluation: Support facility that contributed to the daily function of the station, and not individually significant for the National Register or California Register. Retains Integrity: Yes March 9, 2011 Page & Turnbull, Inc. -64- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California 212: NCO Open Mess Date of Construction: 1957, addition in 1975 Property Type: Support Facility- dining hall Historic Context Notes: The 1,950 square foot, pre-fabricated steel Butler building had an addition of 1,690 square feet constructed in 1975. It was used as a dining hall for the noncommissioned officers. Evaluation: Not individually significant for the National Register or California Register Retains Integrity: Yes 213: Dispensary Date of Construction: 1957 Property Type: Support Facility— medical Historic Context Notes: The 1,000 square foot building was used to provide medical and dental care for Air Force personnel. Evaluation: A support facility for resident personnel, and not individually eligible for the National Register or California Register Retains Integrity: Yes March 9, 2011 Page & Turnbull, Inc. -65- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California 215: Fire Hose House Date of Construction: ca. 1957 Property Type: Ancillary—fire protection Historic Context Notes: All fire hose houses were built between 1957 - 1958. The hydrants were installed first, then these structures were built to shelter the hoses. All of the hose houses were in place before the station became operational in 1958, and all show the interior stencil “Built by 115 CET Wisconsin ANG.” Evaluation: Not individually eligible for the National Register or California Register Retains Integrity: No (Lacks integrity of materials and workmanship because much of the walls and the doors are missing) 217: Bowling Alley Date of Construction: 1961 Property Type: Support Facility- recreation Historic Context Notes: This 1,740 square foot concrete masonry building contained two lanes with pinsetters, one ball-return machine, a frame-counter, frame reset console, operator booth, and men’s/women’s restrooms inside. Evaluation: A recreational facility for resident personnel, and not individually eligible for the National Register or California Register. Also, not age-eligible because it is less than fifty years old. Retains Integrity: Yes March 9, 2011 Page & Turnbull, Inc. -66- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California 225: Airman’s Dining Hall Date of Construction: 1957 Property Type: Support Facility—dining Historic Context Notes: The 4,640 square foot, pre-engineered steel building functioned as the dining hall for commissioned personnel. Evaluation: Support facility for the station, and not individually eligible for the National Register or California Register. Retains Integrity: Yes 226: Fire Hose House Date of Construction: ca. 1957 Property Type: Ancillary—fire protection Historic Context Notes: All fire hose houses were built between 1957 - 1958. The hydrants were installed first, then these structures were built to shelter the hoses. All of the hose houses were in place before the station became operational in 1958, and all show the interior stencil “Built by 115 CET Wisconsin ANG.” Evaluation: Not individually eligible for the National Register or California Register Retains Integrity: Yes (All three walls and the roof are intact, as well as the fire hydrant and hose). March 9, 2011 Page & Turnbull, Inc. -67- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California 230: Commissary Date of Construction: 1957; addition in 1967 Property Type: Support Facility—store Historic Context Notes: Originally a 1,000 square foot prefabricated steel Butler building; a wood-frame addition of 535 square feet was constructed in 1967. The building functioned as a store for groceries and other items. Evaluation: Support facility for the personnel who lived on site. Not individually eligible for the National Register or California Register. Retains Integrity: Yes 232: Fire Hose House Date of Construction: ca. 1957 Property Type: Ancillary—fire protection Historic Context Notes: All fire hose houses were built between 1957 - 1958. The hydrants were installed first, then these structures were built to shelter the hoses. All of the hose houses were in place before the station became operational in 1958, and all show the interior stencil “Built by 115 CET Wisconsin ANG.” Evaluation: Not individually eligible for the National Register or California Register Retains Integrity: No (Lacks integrity of design, materials, and workmanship because the roof and doors are missing.) March 9, 2011 Page & Turnbull, Inc. -68- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California 233: Barracks, aka Airman’s Dormitory and Chapel Date of Construction: 1957 Property Type: Residential- barracks Historic Context Notes: This 2,920 square foot building was once one of six pre-fabricated steel Butler buildings originally used for barracks. The others were removed in the 1970s due to substandard conditions, and personnel without families moved to rented apartments at the bottom of the mountain. This building was converted to a chapel and hobby rooms for photography and ceramics. Evaluation: Support facility for personnel living on site, and not individually eligible for the National Register or California Register Retains Integrity: Yes 234: Fire Hose House Date of Construction: ca. 1957 Property Type: Ancillary—fire protection Historic Context Notes: All fire hose houses were built between 1957 - 1958. The hydrants were installed first, then these structures were built to shelter the hoses. All of the hose houses were in place before the station became operational in 1958, and all show the interior stencil “Built by 115 CET Wisconsin ANG.” Evaluation: Not individually eligible for the National Register or California Register Retains Integrity: Yes (All three walls and the roof are intact). March 9, 2011 Page & Turnbull, Inc. -69- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California 245: Recreation Date of Construction: 1957 Property Type: Support Facility—recreation Historic Context Notes: The 4,660 square foot concrete masonry building contained a BX (base exchange), gymnasium with half-court basketball court, library, billiard room, weight/workout room, barber shop, and projectionist booth for movies. Evaluation: Support facility for recreation. Not individually eligible for the National Register or California Register. Retains Integrity: Yes 250: Auto Maintenance Storage Date of Construction: 1958 Property Type: Ancillary—storage Historic Context Notes: The 360 square foot building is a pre-engineered metal Butler Manufacturing Co. building. Evaluation: Ancillary building, and not individually significant for the National Register or California Register Retains Integrity: Yes March 9, 2011 Page & Turnbull, Inc. -70- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California 275: Swimming Pool Date of Construction: 1957 Property Type: Support Facility—recreation Historic Context Notes: The pool was constructed at the same time as the adjacent gymnasium. It is nine feet deep at one end, and featured a diving board, spiral slide, and filtration system. Evaluation: Recreational facility for personnel on site, and not individually eligible for the National Register or California Register. Retains Integrity: Yes March 9, 2011 Page & Turnbull, Inc. -71- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California 276: Bath House Date of Construction: 1966 Property Type: Support Facility- recreation Historic Context Notes: The 400 square foot concrete masonry building contained men’s and women’s showers, sinks, urinals, and toilets, with a closet/plumbing room in the center. Evaluation: Recreation facility for personnel on site, and not individually eligible for the National Register or California Register. Also, not age eligible because it is less than fifty years old. Retains Integrity: Yes 303: Paint Storage Date of Construction: 1958 Property Type: Ancillary—storage Historic Context Notes: This concrete masonry unit (CMU) building is located next to the sewage treatment ponds at the west end of the facility. Evaluation: Ancillary building, and not individually eligible for the National Register or California Register Retains Integrity: Yes March 9, 2011 Page & Turnbull, Inc. -72- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California 505: Carport Date of Construction: 1958 Property Type: Residential—carport Historic Context Notes: The 4,870 square foot building was constructed adjacent to the family apartments in the cantonment area at the west end of the facility. The two end walls are of stone, and the back wall is concrete. Evaluation: Support facility for the personnel who lived on site, and not individually eligible for the National Register or California Register Retains Integrity: Yes 506: Fire Hose House Date of Construction: ca. 1957 Property Type: Ancillary—fire protection Historic Context Notes: All fire hose houses were built between 1957 - 1958. The hydrants were installed first, then these structures were built to shelter the hoses. All of the hose houses were in place before the station became operational in 1958, and all show the interior stencil “Built by 115 CET Wisconsin ANG.” Evaluation: Not individually eligible for the National Register or California Register Retains Integrity: Yes March 9, 2011 Page & Turnbull, Inc. -73- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California 507: Fire Hose House Date of Construction: ca. 1957 Property Type: Ancillary—fire protection Historic Context Notes: All fire hose houses were built between 1957 - 1958. The hydrants were installed first, then these structures were built to shelter the hoses. All of the hose houses were in place before the station became operational in 1958, and all show the interior stencil “Built by 115 CET Wisconsin ANG.” Evaluation: Not individually eligible for the National Register or California Register Retains Integrity: No (Lacks integrity of design, materials, workmanship, and feeling because it has partially collapsed—the roof and doors are missing.) 508: Fire Hose House Date of Construction: ca. 1957 Property Type: Ancillary—fire protection Historic Context Notes: All fire hose houses were built between 1957 - 1958. The hydrants were installed first, then these structures were built to shelter the hoses. All of the hose houses were in place before the station became operational in 1958, and all show the interior stencil “Built by 115 CET Wisconsin ANG.” Evaluation: Not individually eligible for the National Register or California Register Retains Integrity: No (Lacks integrity of materials and workmanship because the roof and doors is missing) March 9, 2011 Page & Turnbull, Inc. -74- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California 509: Fire Hose House Date of Construction: ca. 1957 Property Type: Ancillary—fire protection Historic Context Notes: All fire hose houses were built between 1957 - 1958. The hydrants were installed first, then these structures were built to shelter the hoses. All of the hose houses were in place before the station became operational in 1958, and all show the interior stencil “Built by 115 CET Wisconsin ANG.” Evaluation: Not individually eligible for the National Register or California Register Retains Integrity: Yes March 9, 2011 Page & Turnbull, Inc. -75- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California 510: Fourplex Apartment Date of Construction: 1958 Property Type: Residential—multiple family housing Historic Context Notes: This 4,880 square foot, two-story wood-frame building was constructed as a residence for Air Force families, while personnel without families lived in steel barracks buildings. Evaluation: One of five identical fourplex apartment buildings that provided on-site housing for personnel and their dependents. Not individually eligible for the National Register or California Register. Retains Integrity: Yes March 9, 2011 Page & Turnbull, Inc. -76- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California 511: Fourplex Apartment Date of Construction: 1958 Property Type: Residential—multiple family housing Historic Context Notes: This 4,880 square foot, two-story wood-frame building was constructed as a residence for Air Force families, while personnel without families lived in steel barracks buildings. Evaluation: One of five identical fourplex apartment buildings that provided on-site housing for personnel and their dependents. Not individually eligible for the National Register or California Register. Retains Integrity: Yes 512: Fourplex Apartment Date of Construction: 1958 Property Type: Residential—multiple family housing Historic Context Notes: This 4,880 square foot, two-story wood-frame building was constructed as a residence for Air Force families, while personnel without families lived in steel barracks buildings. Evaluation: One of five identical fourplex apartment buildings that provided on-site housing for personnel and their dependents. Not individually eligible for the National Register or California Register. Retains Integrity: Yes March 9, 2011 Page & Turnbull, Inc. -77- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California 513: Fourplex Apartment Date of Construction: 1958 Property Type: Residential—multiple family housing Historic Context Notes: This 4,880 square foot, two-story wood-frame building was constructed as a residence for Air Force families, while personnel without families lived in steel barracks buildings. Evaluation: One of five identical fourplex apartment buildings that provided on-site housing for personnel and their dependents. Not individually eligible for the National Register or California Register. Retains Integrity: Yes 514: Fourplex Apartment Date of Construction: 1958 Property Type: Residential—multiple family housing Historic Context Notes: This 4,880 square foot, two-story wood-frame building was constructed as a residence for Air Force families, while personnel without families lived in steel barracks buildings. Evaluation: One of five identical fourplex apartment buildings that provided on-site housing for personnel and their dependents. Not individually eligible for the National Register or California Register. Retains Integrity: Yes March 9, 2011 Page & Turnbull, Inc. -78- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California 515: Triplex Apartment Date of Construction: 1958 Property Type: Residential—multiple family housing Historic Context Notes: This 3,870 square foot, two-story wood-frame building was constructed as a residence for Air Force families, while personnel without families lived in steel barracks buildings. Evaluation: One of two identical triplex apartment buildings with integral carports that provided on-site housing for personnel and their dependents. Not individually eligible for the National Register or California Register. Retains Integrity: No (Lacks integrity of materials and workmanship due to severe damage caused by weathering that has removed a large amount of interior materials). 516: Commander’s House Date of Construction: 1958 Property Type: Residential—single family dwelling Historic Context Notes: This 1,527 square foot, one-story wood-frame building provided housing for the commander of the station. In later years, after the base closed, it was used by the caretaker for the site. Evaluation: Housing for personnel, and not individually eligible for the National Register or California Register Retains Integrity: Yes March 9, 2011 Page & Turnbull, Inc. -79- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California 517: Triplex Apartment Date of Construction: 1958 Property Type: Residential—multiple family housing Historic Context Notes: This 3,870 square foot, two-story wood-frame building was constructed as a residence for Air Force families, while personnel without families lived in steel barracks buildings. Evaluation: One of two identical triplex apartment buildings with integral carports that provided on-site housing for personnel and their dependents. Not individually eligible for the National Register or California Register. Retains Integrity: No (Lacks integrity of materials and workmanship due to severe damage caused by weathering that has removed a large amount of interior materials.) March 9, 2011 Page & Turnbull, Inc. -80- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California 700: Communications Transmitter/Receiver (GATR Building) Date of Construction: 1962 Property Type: Special Military Use - GATR Historic Context Notes: The building was constructed as the second Ground to Air Transmitter Receiver (GATR) communications building. GATR moved to Mt. Thayer in 1962 when the AN/FPS-24 radar was constructed on Mt. Umunhum, so that radio signals would be interfere. Evaluation: The building is not of significant design or construction. Its function was important within the station as the communication building that relayed information from the radars to Air Force pilots, but it was not the first GATR building at Almaden AFS. Furthermore, it is not individually eligible for the National Register or California Register due to lack of integrity. Retains Integrity: No (Lacks integrity of workmanship, feeling, and association because the GATR equipment was removed. Without the equipment, the shell of the building does not convey the connection to this historic use, and the building resembles other CMU buildings at the facility, which were used in a variety of ways.) March 9, 2011 Page & Turnbull, Inc. -81- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California 715/722: Security Sentry House Date of Construction: 1966 Property Type: Support Facility—security Historic Context Notes: The small wood-frame building is located down the road from the GATR facility on Mt. Thayer. It has been recorded in documents as numbering either Building 715 or 722. Evaluation: Support facility, and not individually eligible for the National Register or California Register. Also, not age-eligible because it is less than fifty years old. Retains Integrity: No (Lacks integrity of materials and workmanship due to missing door and windows.) March 9, 2011 Page & Turnbull, Inc. -82- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California TELCO Date of Construction: 1957 Property Type: Support Facility—telephone company building Historic Context Notes: Concrete Masonry Unit (CMU) construction. Telephone lines came in from the phone company, and the TELCO building acted as a demarcation point, where local lines extended throughout the facility. Evaluation: Support facility, and not individually eligible for the National Register or California Register Retains Integrity: No (Lacks integrity of materials and association as all telecom equipment has been removed). March 9, 2011 Page & Turnbull, Inc. -83- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California VII. CONCLUSION The former Almaden Air Force Station contributed to NORAD’s Early Warning Radar system along the Pacific Coast from 1958 to 1980. Its radars worked in conjunction with those at nine other Air Force stations in California, and all were connected to the SAGE network—the automated control system for tracking and intercepting enemy bomber aircraft from about 1960 through the 1980s. The station functioned much like the others in California, and its built resources were very similar. The other sites also contained concrete and steel radar towers, pre-engineered steel Butler buildings, and wood frame residential buildings in similar styles. The types of radars used at the former Almaden AFS were also used at the other stations. Consequently, the former Almaden AFS does not stand out as particularly significant compared to other radar stations in California, nor did it have enhanced responsibilities as a command center. It therefore does not appear eligible as a historic district on the National Register of Historic Places or the California Register of Historical Resources. Of the forty-seven resources examined at the former Almaden Air Force Station on Mt. Umunhum and Mt. Thayer, none of the properties were found individually eligible for listing on the National Register or the California Register by Page & Turnbull, whether at the local, state, or national level. Most are support facilities or residences that are not significant architecturally and did not have an important function individually within the station. The four extant buildings that were most important to the station include Building 100 (the Operations Building); Building 102 (the concrete tower for the AN/FPS-24 radar); Building 108 (the steel tower for the AN/MPS-14 radar); and Building 110 (the original GATR building). However, these are not eligible due to lack of historic integrity. The concrete radar tower at Point Arena may better represent the AN/FPS-24 radar within the state, as it was the first of its type to be built and the building has already had complete exterior hazmat abatement. A rare fully intact AN-FPS-24 (the radar sail remains) is located at Camp Hero on Long Island, New York. A summary table of the report’s conclusions is found in I. Introduction (See Table 1). In conclusion, no buildings or structures at the former Almaden Air Force Station were determined eligible for listing, either as a historic district or individually, on the National Register of Historic Places or the California Register of Historical Resources. March 9, 2011 Page & Turnbull, Inc. -84- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California VIII. RECOMMENDATIONS Although none of the buildings, nor the site, qualify for the National Register of Historic Places or the California Register of Historical Resources, some of the structures are in good condition and are important representations of the historic background of the former base. Page & Turnbull was asked to provide recommendations for buildings that would be appropriate for re-use, should the District’s site planning efforts determine that retaining one or more buildings is a viable option. Several individual buildings were found to be important, but they lacked sufficient integrity to be eligible for the National Register or California Register. However, because of their historic function or continuing potential for usefulness, these facilities could provide excellent opportunities for interpretation and/or reuse. HISTORIC INTERPRETATION (BUILDINGS 102, 108, 110) As previously discussed, the buildings that best represent the historic function of the former Almaden Air Force Station are all clustered at the top of the mountain. They include the concrete radar tower for the AN/FPS-24 (Building 102); the steel tower for the AN/MPS-14 (Building 108); and the Training Building (Building 110). It may be fair to say that nearly all the other buildings present at the former Almaden AFS were designed solely to support the functions of these facilities (Figure 35). These buildings also exemplify typical construction methods, such as reinforced concrete construction and the prevalent use of pre-engineered steel Butler buildings. Thus, they are excellent candidates for interpretation. Figure 35. Buildings 102, 108, and 110 in about 1969. (Source: http://www.radomes.org/museum/) March 9, 2011 Page & Turnbull, Inc. -85- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California Building 102 is the most impressive structure at the site. If it were to be retained, it could potentially be used as an interpretive center that discusses the historic use of the former Almaden AFS. Interpretive signage about the site, the building, and the AN/FPS-24 that was once located there could be installed. Any option for re-use of building 102 would require structural upgrades. If the interior space is utilized, additional code upgrades would be required and hazardous openings would need to be closed with appropriate screens or glazing. Conversely, the building could be fully sealed, the interior unused by visitors. In this case, the building would continue to serve as a local icon, and interpretive materials could be placed on the exterior. Figure 36. Building 108 and 110, ca. 1969. (Source: http://www.radomes.org/museum/) Figure 37. Buildings 108 and 110, 2010. (Source : Page & Turnbull, February 2010). Building 108 is a steel structure that is not likely to be reused. However, its distinctive design makes it attractive for interpretation, and signage discussing its historic function could be placed at the base. Building 110 is a good example of a typical steel Butler building, and it also housed an important communication function in the early days of the AFS (Figures 36 and 37). This building could be used for interpretation or another function. Access to this cluster of buildings is an important consideration. If vehicular access is anticipated, parking areas are already in place adjacent to Buildings 102 and 110. However, because the site March 9, 2011 Page & Turnbull, Inc. -86- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California presents a spectacular natural viewpoint, the Midpeninsula Regional Open Space District may choose to restrict vehicle access to this area in order to eliminate soundscape intrusions from traffic, car stereos, slamming doors, etc. In this case, a parking area could be established lower down the mountain and visitors would walk up to the peak. However, access for the disabled would need to be provided to the top. POTENTIAL MROSD FACILITIES (BUILDINGS 211, 212, 884B) In addition to historic interpretation, there are also several buildings at the site that present good opportunities for reuse in support of day-to-day Midpeninsula Regional Open Space District operations, should such facilities be required. These include the Automotive Maintenance Facility (Building 211), which could be reused as a service/storage area for MROSD vehicles. Likewise, the adjacent Building 212 could provide storage facilities and a small office area for the MROSD. This Butler building is particularly attractive because it is screened behind a small slope and thus does not interrupt views in the area. Fire protection remains an important consideration for the MROSD, and thus the Water Tower (884B) located approximately 200 yards upslope from the Auto Maintenance Shop might be retained. It appears to be in good condition and is generally screened by vegetation. March 9, 2011 Page & Turnbull, Inc. -87- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California IX. BIBLIOGRAPHY PUBLISHED California Office of Historic Preservation, Technical Assistance Series No. 7: How to Nominate a Resource to the California Register of Historic Resources. Sacramento, CA: California Office of State Publishing, 4 September 2001. National Park Service. National Register Bulletin: How to Apply the National Register Criteria for Evaluation. Washington D.C.: National Park Service, 1997. National Park Service, Western Region. Historic American Buildings Survey: Mill Valley Air Force Station, HABS No. CA-2615. San Francisco, CA: National Park Service, 1995. Winkler, David F. Searching the Skies: The Legacy of the United States Cold War Defense Radar Program. Champaign, Il: United States Air Force Headquarters Air Combat Command, June 1997. INTERNET “751st Radar Sqdn., Mount Laguna AFS, CA,” Website accessed on 9 March 2010 from: http://www.radomes.org/museum/recent/MountLagunaAFSCA.html “Aerospace Defense Command,” Wikipedia. Website accessed on 3 March 2010, http://en.wikipedia.org/wiki/Aerospace_Defense_Command “Almaden Air Force Station,” Wikipedia. Website accessed on 16 March 2010 from: http://en.wikipedia.org/wiki/Almaden_Air_Force_Station “April 2004 SitRep,” Air Defense Radar Museum. Website accessed on 11 March 2010 from: http://www.radomes.org/museum/ “Boron Federal Prison Camp/Boron AFS,” Wikimapia. Website accessed on 15 March 2010 from: http://wikimapia.org/3945077/Boron-Federal-Prison-Camp-Boron-AFS-site “Cambria Air Force Radar Station Conversion Project Proposal,” Website accessed on 9 March 2010 from: http://www.macronet.org/airbase/airforce.html “Cold War,” Wikipedia. Website accessed on 2 March 2010, http://en.wikipedia.org/wiki/Cold_War “Klamath Air Force Station,” Wikimapia. Website accessed on 15 March 2010 from: http://wikimapia.org/5166808/Klamath-Air-Force-Station “Lompoc Air Force Station,” Website accessed on 15 March 2010 from: www.radomes.org “Madera Air Force Station,” The California State Military Museum, Website accessed on 9 March 2010 from: http://www.militarymuseum.org/Madera%20AFS.html. “Mill Valley AFS,” Website accessed on 9 March 2010 from: http://www.militarymuseum.org/MillValleyAFS.html. March 9, 2011 Page & Turnbull, Inc. -88- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California “Mount Laguna AFS,” Website accessed on 9 March 2010 from: http://wikimapia.org/5329703/Mount-Laguna-AFS-site “Mt. Tamalpais West Peak/Mill Valley AFS,” Website accessed on 9 March 2010 from: http://wikimapia.org/1482223/Mt-Tamalpais-West-Peak-Mill-Valley-AFS-site “NORAD Fact Sheet,” Online Air Defense Radar Museum. Accessed on 23 February 2010, http://www.radomes.org/museum/data/newsletters/NORAD79-1.jpg “North American Aerospace Defense Command,” Wikipedia. Website accessed on 2 March 2010, http://en.wikipedia.org/wiki/NORAD “Point Arena Air Force Station.” Wikipedia. Website accessed on 9 March 2010 from; http://en.wikipedia.org/wiki/Point_Arena_Air_Force_Station “Potsdam Conference,” Wikipedia. Website accessed on 2 March 2010, http://en.wikipedia.org/wiki/Potsdam_Conference “Radar,” Wikipedia. Website accessed on 2 March 2010, http://en.wikipedia.org/wiki/radar “Red Bluff Air Force Station,” The California State Military Museum, Website accessed on 15 March 2010 from: http://www.militarymuseum.org/RedBluffAFS.html. Site Survey Summary Sheet for DERP-FUDS site No. J09CA099900: Almaden Air Force Station.” Corps FUDS. Website accessed on 4 March 2010 from: http://www.corpsfuds.org/reports/INPR/J09CA0999inpr.pdf “Strategic Air Defense Systems,” Federation of American Scientists, Website accessed from: http://www.fas.org/nuke/guide/usa/airdef/ “The Mission of ADC,” Aerospace Defense Command Pamphlet 190-1, September 1963. Website accessed on 23 February 2010 from: www.radomes.org/museum INTERVIEWS Email correspondence with Basim Jaber, 9 March 2010. ____, 23 March 2010. ____, 2 March 2011. ____, 4 March 2011. Telephone interview with Basim Jaber, local resident and chronicler of information about the former Almaden AFS, 2 March 2010. Telephone interview with David Schwaderer, local chronicler of the former Almaden AFS, 1 March 2010. OTHER March 9, 2011 Page & Turnbull, Inc. -89- Historic Resource Study Final Draft with Update Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California 682nd Radar Squadron, Welcome to 682nd Radar Squadron, Almaden AFS, California (n.d.; post-1976) 2. Gould Architects, Mt. Umunhum Facilities Inventory and Evaluation, 1994. U.S. Army, “Defense Environmental Restoration Program Formerly Used Defense Sites, Findings and Determination of Eligibility, Almaden Air Force Station (Z-96), Santa Clara, California, Site No. J09CA099900” (2 December 1991). March 9, 2011 Page & Turnbull, Inc. -90- JRP Historical Consulting, LLC 2015 APPENDIX B Page & Turnbull 2011 Addendum PEER REVIEW – MT UMUNHUM RADAR TOWER, BUILDING 102 Historic Resource Study Addendum August 4, 2011 Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, CA Prepared for Mid-Peninsula Regional Open Space District Los Altos, CA Prepared by page & turnbull, inc. 1000 Sansome Street, Ste. 200, San Francisco CA 94111 415.362.5154 / www.page-turnbull.com Historic Resource Study Addendum Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California TABLE OF CONTENTS TABLE OF CONTENTS ..................................................................................................... 1 I. INTRODUCTION............................................................................................................ 2 II. HISTORIC CONTEXT: THE COLD WAR IN SANTA CLARA COUNTY (1945 – 1991) ................................................................................................................................... 2 MOFFETT FEDERAL AIRFIELD.................................................................................................. 2 ONIZUKA AIR FORCE STATION.............................................................................................. 3 MILITARY –RELATED TECHNOLOGICAL DEVELOPMENT IN SANTA CLARA COUNTY. 5 III. EVALUATION DISCUSSION....................................................................................... 8 THE NATIONAL REGISTER AND CALIFORNIA REGISTER – LOCAL SIGNIFICANCE ........ 8 LOCAL DESIGNATION ............................................................................................................. 8 IV. CONCLUSION.............................................................................................................. 9 V. BIBLIOGRAPHY .......................................................................................................... 10 August 4, 2011 Page & Turnbull, Inc. -1- Historic Resource Study Addendum Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California I. INTRODUCTION This Historic Resource Study Addendum has been completed at the request of the Midpeninsula Regional Open Space District. It develops upon Page & Turnbull’s “Historic Resource Study: Former Almaden Air Force Station” (9 March 2011), which primarily discusses the context of the Cold War in the U.S. and the statewide network of Cold War-era U.S. Air Force radar stations in California. This addendum examines more closely the local historic context and potential local significance of buildings at the former Almaden Air Force Station (AFS), which is situated at the summits of Mt. Umunhum and Mt. Thayer in Santa Clara County, California. II. HISTORIC CONTEXT: THE COLD WAR IN SANTA CLARA COUNTY (1945 – 1991) The following section provides a discussion of other military installations that operated during the Cold War in Santa Clara County. There is also a discussion of microwave, missile, satellite, and computer industries that received government funding to develop military technology. This Historic Context section has been provided in order to evaluate the former Almaden Air Force Station for local significance in the National Register of Historic Places, the California Register of Historical Resources, and the Santa Clara County Historic Resources Inventory. MOFFETT FEDERAL AIRFIELD Moffett Federal Airfield, originally called the Sunnyvale Naval Air Station, was first constructed in 1931. More commonly called Moffett Field, the facility is located in northern Mountain View on the east side of U.S. Route 101. From World War II through the Cold War, Moffett Field was the primary military presence in Silicon Valley. It is perhaps best known as the home of Hangar One, which was constructed to contain a dirigible called the USS Macon. During World War II, the base was home for many non-rigid blimps and air balloons. In the post-war years, Moffett Field became a major Naval Air Transport Service Squadron Center. The base moved into the jet age, extending Moffett Field’s landing strips and modifying its hangars. During the Korean Conflict in 1950, Moffett Field housed the first night jet fighter in the service. More support buildings and landing facilities were built during this time period, and the base became popular for testing new aircraft and jet operations. In 1963, Moffett Field became the home of the Navy’s first land-based anti-submarine patrol aircraft, the Orion Hunter. These planes operated out of Moffett Field for the next 30 years. During the 1970s, the base became the headquarters of the Commander Patrol Wings, U.S. Pacific Fleet, responsible for patrolling 93 million square miles of August 4, 2011 Page & Turnbull, Inc. -2- Historic Resource Study Addendum Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California ocean from Alaska to Hawaii. Operations continued until the Navy officially closed Moffett Field in July 1, 1994, and use of the base was transferred to NASA Ames Research Center.1 Figure 1. Bird’s eye view of Moffett Field, looking northwest. 15 October 2008. (Source: http://en.wikipedia.org/wiki/File:Kluft-photo-Moffett-Federal-Airfield-Oct-2008Img_1911.jpg) In February 1994, the United States Naval Air Station, Sunnyvale was listed as a National Register Historic District by the National Park Service. It is significant at the national level for its association with the expanding coastal defense capabilities of the U.S. Navy and airship technology during the era between 1932 and 1945.2 Hangar One was determined eligible for nomination to the National Register of Historic Places circa 2001 by the U.S. Navy, in consultation with the California State Historic Preservation Officer. Hangar One was inducted as a Naval Historical Landmark in the early 1950s and as a California Historic Civil Engineering Landmark by the San Francisco Section, American Society of Civil Engineers in May 1975. It is also listed in the Santa Clara County Heritage Resource Inventory.3 Military contributions during Cold War are outside Moffett Field’s defined period of significance. ONIZUKA AIR FORCE STATION Onizuka Air Force Station (AFS) is a former United States Air Force installation in Santa Clara County, just outside the city limits of Sunnyvale. The station was developed on land immediately 1 “Moffett Field History Tour,” NASA Ames Research Center Historic Preservation Office. Website accessed on 13 July 2011 from: http://historicproperties.arc.nasa.gov/history/history1.html 2 “Hangar One (Mountain View, California),” Wikipedia. Website accessed on 13 July 2011 from: http://en.wikipedia.org/wiki/Hangar_One_%28Mountain_View,_California%29 3 Page & Turnbull, “Hangar One, Moffett Field, California: Re-Use Guidelines,” Prepared for NASA/Ames Research Center (24 August 2001) 7-8, 13. August 4, 2011 Page & Turnbull, Inc. -3- Historic Resource Study Addendum Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California south of Moffett Field. The main building, known locally as the “Blue Cube,” is large, pale blue, and windowless. It is surrounded by an array of parabolic dish antennas used for communication with remote tracking stations that control military satellites. Built in 1960 on land purchased from Lockheed, the station was originally known as the Air Force Satellite Test Center. It was later renamed the Air Force Satellite Control Facility and Sunnyvale Air Force Station. In 1986, the base was renamed Onizuka Air Force Base in honor of Lt. Col. Ellison Onizuka, USAF, one of the astronauts who died in the Space Shuttle Challenger disaster on 28 January 1986. On 26 January 1994, Onizuka Air Force Base was renamed Onizuka Air Force Station.4 Figure . The “Blue Cube” at Onizuka Air Force Station (Source: http://en.wikipedia.org/wiki/File:Lockheed%27s_%22Blue_Cube%22.jpg) Onizuka AFS was operated by the 21st Space Operations Squadron, a geographically separated unit (GSU) of the 50th Space Wing. The facility contained Detachment 2 of the Space and Missile Systems Center and a branch of the National Reconnaissance Office.5 The latter was a classified operation that was created in September 1961 in response to the Soviet launch of Sputnik. Its purpose was overseeing “all satellite and overflight reconnaissance projects whether overt or covert.”6 It operated at Onizuka AFS from 1961 to 2007. In general, between 1960 and 1970, Onizuka AFS was the exclusive satellite control center for all military satellites, international communications, space operations, space shuttle, and NASA communications. It was the primary 4 “Onizuka Air Force Station,” Wikipedia. Website accessed on 15 July 2011 from: http://en.wikipedia.org/wiki/Onizuka_Air_Force_Station 5 Ibid. 6 “The NRO,” National Reconnaissance Office, Website accessed on 15 July 2011 from: http://www.nro.gov/about/nro/index.html August 4, 2011 Page & Turnbull, Inc. -4- Historic Resource Study Addendum Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California military communications facility in the U.S., with no other comparable backup facility for 30 years.7 The AFS closed on 28 July 2010, and operations were moved to the new Ellison Onizuka Satellite Operations Facility at Vandenberg Air Force Base. Based on its significance as a “mid-century scientific site associated with important geo-political developments during the Cold War,” the former Onizuka AFS was found by historic architecture consultant Frederick Knapp in 2008 to be potentially eligible for the local (City of Sunnyvale) register. The buildings were not age-eligible for listing in the California Register and National Register at the time of evaluation, but were found to possibly qualify under Criterion Consideration G: Properties that have Achieved Significance Within the Past Fifty Years.8 MILITARY –RELATED TECHNOLOGICAL DEVELOPMENT IN SANTA CLARA COUNTY Missile, Satellite, and Microwave Technology During the Cold War and the arms race, the Korean conflict, and the space program, the Department of Defense (DOD) ordered numerous high-technology products from armament factories in California. Many companies established Research and Development (R&D) departments and production facilities in Santa Clara County, where Stanford University provided bright engineers and scientists. These burgeoning companies were largely supported by the DOD’s demand for electronic products.9 Examples of such firms are FMC (formerly Food Machinery Corporation), GTE Corporation (formerly General Telephone & Electronics Corporation), Varian Associates, Westinghouse Electronic Corporation, and Lockheed. During the 1960s, FMC built the M113 Armored Personnel Carrier (APC), the Bradley Fighting Vehicle, and the XR311 prototype military vehicle at its former facility in Santa Clara, California.10 Automatic Electric, a subsidiary of GTE, supplied electronic switching equipment for the DOD’s global communications systems, and GT&E International, another subsidiary of GTE, produced earth-based stations for both foreign and domestic markets. Though GTE had offices in Palo Alto, it also operated offices throughout the country and it is unclear through basic research which production departments were located in Palo Alto. Varian Associates was founded in Palo Alto in 1948, following the invention of a microwave device called 7 “City of Sunnyvale Report: Heritage Preservation Commission,” City of Sunnyvale (6 August 2008): 3-4. Website accessed on 15 July 2011 from: http://sunnyvale.ca.gov/LinkClick.aspx?fileticket=rRYNovK3ux0%3D&tabid=662 8 Ibid: 10. 9 Martin Groger, “Importance of Military Funding,” The Silicon Valley Story. Website accessed on 14 July 2011 from: http://www.silicon-valley-story.de/sv/militFunding.html 10 “FMC Corporation,” Wikipedia. Website accessed on 14 July 2011 from: http://en.wikipedia.org/wiki/FMC_Corporation August 4, 2011 Page & Turnbull, Inc. -5- Historic Resource Study Addendum Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California the klystron at Stanford University by Russell and Sigurd Varian. During the Cold War period, Varian Associates developed vacuum electron tubes, power amplifiers, power supplies, microwave components, electromagnets for satellite communications, and radar and electronic warfare applications.11 Westinghouse had a plant in Sunnyvale that manufactured launch tubes for Trident submarines beginning ca. 1968. Lockheed opened its R&D department in the Stanford Research Park in 1956 and started Lockheed Missiles and Space Company (LMSC) in Sunnyvale. Between 1959 and 1978, the company manufactured the U.S. Navy’s submarine-launched ballistic missiles called UGM-27 Polaris and UCM-73 Poseidon.12 Despite using military funding during the Cold War, these technological developments likely took place in various corporations’ offices and manufacturing plants, where non-military development and production also occurred. It does not appear that any buildings have been identified in the past as historically significant in relation to this Cold War-era context. Based on this preliminary research, no particular buildings stand out as being significant primarily for this context. Government-Sponsored Computer Technology Development According to the National Park Service’s “Santa Clara County: California’s Historic Silicon Valley: A National Register of Historic Places Travel Itinerary,” America’s defense spending during the Cold War Era, when research and development strove to keep abreast of the Soviet Union, helped [develop the hi-tech corridor of Silicon Valley]. After the Soviets launched the first man-made satellite, Sputnik, in 1957, President Eisenhower created the Advance[d] Research Projects Agency, which was part of the Department of Defense, in 1958. After launching the first successful U.S. Satellite, the Advance Research Projects Agency turned its attention to the potential of computers.13 The role of federal involvement in computer development is further explained by the Breakthrough Institute’s Case Studies in American Innovation: A New Look at Government Involvement in Technological Innovation: From the beginnings of the computer industry, federal and military agencies promoted vital basic research into computing hardware and deployed early computers throughout the government. As economist Vernon Ruttan writes, “The role of the military in driving the development of computer, semiconductor and software technologies cannot be overemphasized. These technologies were, until well into the 1960s, nourished by markets that were almost completely dependent 11 “Company Information, History,” CPI: Communications & Power Industries. Website accessed on 14 July 2011 from: http://www.cpii.com/history.cfm 12 Andreas Parsch, “Lockheed UCM-73 Poseidon,” Directory of U.S. Military Rockets and Missiles, Website accessed on 14 July 2011 from: http://www.designation-systems.net/dusrm/m-73.html 13 “Economic History,” Santa Clara County: California’s Historic Silicon Valley. National Park Service. Website accessed on 13 July 2011 from: http://www.nps.gov/nr/travel/santaclara/economic.htm August 4, 2011 Page & Turnbull, Inc. -6- Historic Resource Study Addendum Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California on the defense, energy and space industries.” In fact, the ENIAC, the first electronic computer, was built in 1945 to crunch numbers for the Army Ballistics Research Laboratory. In the 1950s, the Army Signal Corps funded research into semiconductors, and weapons labs at the Atomic Energy Commission were the first purchasers of supercomputers, the ancestors of today's desktop PCs. NASA, the Department of Defense, the National Center for Atmosphere Research, and the U.S. Weather Bureau commissioned their own supercomputers soon after. Perhaps most importantly, the Air Force’s SAGE air defense project generated numerous innovations in computing design and production during the early 1950s, including cheap manufacturing of computer memory, communication between computers, and the use of keyboard terminals. The government was also heavily involved in the development of computer software. Defense agencies funded the basic R&D that led to early computer programs and programming languages. During the 1970s, in fact, defense spending fueled over half of all academic computing research, and grants from the military's Advanced Research Project Agency (ARPA) established the first university computer science programs at MIT, Stanford, Carnegie Mellon and elsewhere. The defense establishment took computing seriously. In 1962, ARPA’s computer research budget exceeded that of all other countries combined; by 1970, its funding had increased fourfold. The Department of Defense was the single largest purchaser of software well into the 1980s, ensuring the consistent market demand that fueled an ever-growing industry. In addition to producing major computing advances through research funding and direct acquisition, the federal government also cultivated the innovators and engineers of the modern computer industry. Many of the minds behind the groundbreaking work at Xerox’s Palo Alto Research Center (PARC), the famous computer research center, and at corporations like Microsoft and Apple came straight from government agencies… No less important, however, were the innumerable programmers, system designers, and computer theorists who cut their teeth and honed their skills at ARPA. So many veterans of ARPA and ARPA-supported university programs came to work at Xerox PARC that insiders there jokingly referred to an “ARPA Army.” These numerous veterans of government-funded programs helped Xerox PARC develop the graphical user interface and the Alto, the world's first modern PC, and later scattered to run startup firms like Apple, Microsoft, and Adobe. Popular myths about the rise of the PC make little mention of the government, but in reality, public funding built the foundations of personal computing. The government’s prescient investments in computer research, hardware and software deployment, and computer science education unleashed a transformative technology and helped build a massive industry from the ground up.14 In Santa Clara County, Stanford University and the Stanford Research Institute were provided government funding to develop computer technology through ARPA. The Palo Alto Research The Breakthrough Institute, Case Studies in American Innovation: A New Look at Government Involvement in Technological Innovation (April 2009). Website accessed on 13 July 2011 from: http://thebreakthrough.org/blog//2009/04/silicon_valley_garage_or_gover-print.html 14 August 4, 2011 Page & Turnbull, Inc. -7- Historic Resource Study Addendum Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California Center (PARC), Microsoft, Apple, and Adobe were staffed by early computer engineers who may have originated from government positions. These historic developments likely took place on the Stanford campus and in various fledgling companies’ offices, where non-military development also occurred.. It does not appear that any buildings have been identified in the past as historically significant in relation to Cold War-era development. Based on this preliminary research, no particular buildings stand out as being significant primarily for this context. III. EVALUATION DISCUSSION THE NATIONAL REGISTER AND CALIFORNIA REGISTER – LOCAL SIGNIFICANCE The Department of Defense (DOD) created a military presence in Silicon Valley and was influential in the development of the high-tech industry. Based on the historic context described above, the former Onizuka AFS appears to contain the most significant and presumably intact buildings (at the time of historic evaluation) that represent the Cold War era in Santa Clara County, as it had extremely important and highly unique military responsibilities during its period of operation. The former Almaden Air Force Station operated within this climate of defense spending and technological development. The facility may have been considered locally significant under National Register Criterion A/California Register Criterion 1 (associated with significant events) as the only Cold War-era military radar facility in Santa Clara County. Nevertheless, the historic context of U.S. military influence in Santa Clara County does not alter the fact that the Almaden AFS facility no longer retains integrity. To be considered historic resources eligible for local, state, or national listing, properties must be both historically significant and retain sufficient integrity to represent that significance. The buildings at the former Almaden Air Force Station, though constructed in the early years of Cold War-era defense advancement, do not retain sufficient materials, workmanship, feeling, or association to maintain their historic integrity. This includes Building 102 (the Radar Tower), which, though a large and visually identifiable structure from the base of the mountain, does not retain the radar sail or interior mechanics that associate it with its former defense function. LOCAL DESIGNATION The Santa Clara County Municipal Code’s “Article II. Landmark Designation” describes the criteria for listing a property in the local inventory: Sec. C17-5. Designation criteria. For the purposes of this chapter, the Board of Supervisors may designate those historic resources as “landmarks” which meet the following designation criteria: August 4, 2011 Page & Turnbull, Inc. -8- Historic Resource Study Addendum Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California A. Fifty years or older. If less than 50 years old, sufficient time must have passed to obtain a scholarly perspective on the events or individuals associated with the historic resource and/or the historic resource is a distinctive or important example of its type or style; and B. Retains historic integrity. If a historic resource was moved to prevent demolition at its former location, it may still be considered eligible if the new location is compatible with the original character of the property; and C. Meets one or more of the following criteria of significance: 1. Associated with events that have made a significant contribution to the broad patterns of local or regional history, or the cultural heritage of California or the United States; 2. Associated with the lives of persons important to local, California or national history; 3. Embodies the distinctive characteristics of a type, period, region, or method of construction, or represents the work of a master or possesses high artistic values; or 4. Yielded or has the potential to yield information important to the pre-history or history of the local area, California, or the nation. (Ord. No. NS-1100.96, 10-17-06)15 Because historic integrity is a crucial component to designation at the local level, the former Almaden Air Force Station was not found eligible for listing in the Santa Clara County Heritage Resource Inventory. IV. CONCLUSION Page & Turnbull’s “Historic Resource Study: Former Almaden Air Force Station” (9 March 2011) evaluated the former Almaden Air Force Station for eligibility for listing in the National Register of Historic Places and the California Register of Historical Resources at the national and state-wide level of significance. Because the property did not contain unique facilities or functions within the California network of Cold War-era radar Air Force Stations, it was not found to be historically significant. Other facilities have more intact examples of radars or held a more significant role in the network. Furthermore, due to degradation and alterations to numerous buildings on the property, the Alamden Air Force Station as a whole does not retain integrity as a potential historic district. Likewise, the individual buildings either do not possess individual significance or do not retain sufficient integrity to convey their potential significance. 15 “Article II. Landmark Designation,” Santa Clara County Code, Santa Clara County Government. Website accessed on 14 July 2011 from: http://www.sccgov.org/scc_ordinance/41702000.HTM August 4, 2011 Page & Turnbull, Inc. -9- Historic Resource Study Addendum Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California Based on the local historic context above, the former Onizuka AFS appears to best represent significant military responsibilities in Santa Clara County during the Cold War. Furthermore, the evaluation discussion emphasizes the requirements of significance and integrity at the local level. Neither the former Almaden Air Force Station, nor any of the individual buildings on the property, were found eligible for listing in the National Register or California Register for local significance. The facility and its buildings are also not eligible for local listing in the Santa Clara County Heritage Resource Inventory. V. BIBLIOGRAPHY “Article II. Landmark Designation,” Santa Clara County Code, Santa Clara County Government. Website accessed on 14 July 2011 from: http://www.sccgov.org/scc_ordinance/41702000.HTM “City of Sunnyvale Report: Heritage Preservation Commission,” City of Sunnyvale (6 August 2008). Website accessed on 15 July 2011 from: http://sunnyvale.ca.gov/LinkClick.aspx?fileticket=rRYNovK3ux0%3D&tabid=662 “Company Information, History,” CPI: Communications & Power Industries. Website accessed on 14 July 2011 from: http://www.cpii.com/history.cfm “Economic History,” Santa Clara County: California’s Historic Silicon Valley. National Park Service. Website accessed on 13 July 2011 from: http://www.nps.gov/nr/travel/santaclara/economic.htm “FMC Corporation,” Wikipedia. Website accessed on 14 July 2011 from: http://en.wikipedia.org/wiki/FMC_Corporation Groger, Martin. “Importance of Military Funding,” The Silicon Valley Story. Website accessed on 14 July 2011 from: http://www.silicon-valley-story.de/sv/militFunding.html “Hangar One (Mountain View, California),” Wikipedia. Website accessed on 13 July 2011 from: http://en.wikipedia.org/wiki/Hangar_One_%28Mountain_View,_California%29 “Moffett Field History Tour,” NASA Ames Research Center Historic Preservation Office. Website accessed on 13 July 2011 from: http://historicproperties.arc.nasa.gov/history/history1.html Page & Turnbull, “Hangar One, Moffett Field, California: Re-Use Guidelines,” Prepared for NASA/Ames Research Center (24 August 2001). Parsch, Andreas. “Lockheed UCM-73 Poseidon,” Directory of U.S. Military Rockets and Missiles. Website accessed on 14 July 2011 from: http://www.designation-systems.net/dusrm/m73.html August 4, 2011 Page & Turnbull, Inc. -10- Historic Resource Study Addendum Former Almaden Air Force Station Mt. Umunhum and Mt. Thayer, Santa Clara County, California “Onizuka Air Force Station,” Wikipedia. Website accessed on 15 July 2011 from: http://en.wikipedia.org/wiki/Onizuka_Air_Force_Station The Breakthrough Institute, Case Studies in American Innovation: A New Look at Government Involvement in Technological Innovation (April 2009). Website accessed on 13 July 2011 from: http://thebreakthrough.org/blog//2009/04/silicon_valley_garage_or_gover-print.html “The NRO,” National Reconnaissance Office. Website accessed on 15 July 2011 from: http://www.nro.gov/about/nro/index.html August 4, 2011 Page & Turnbull, Inc. -11- JRP Historical Consulting, LLC 2015 APPENDIX C Archives & Architecture 2014 Report PEER REVIEW – MT UMUNHUM RADAR TOWER, BUILDING 102 A R C H I V E S & A R C H I T E C T U R E , L L C PO Box 1332 San Jose CA 95109-1332 1.408.297.2684 OFFICE 1.408.228.0762 FAX April Halberstadt, Chair Santa Clara County Historical Heritage Commission C/o Michele Napier, Clerk County of Santa Clara 70 West Hedding Street, 7th Floor San José, CA 95110 Re: Mount Umunhum Radar Tower Honorable Chair and Members of the Commission: ARCHIVES & ARCHITECTURE, LLC is pleased to have had the opportunity to investigate the possibility of designating the Radar Tower at Mount Umunhum as a Santa Clara County Landmark. Attached to this letter is a narrative report documenting our findings, and DPR523 series recording forms that detail the physical aspects of the AN/FPS‐24 Radar Tower sitting at the crest of Mount Umunhum in the Sierra Azul Open Space Preserve. ARCHIVES & ARCHITECTURE, LLC is a local Cultural Resources Management firm with a long history of serving the citizens of Santa Clara County and its public agencies. Founded in 1989 by the late Glory Anne Laffey, the firm’s principals today include Franklin Maggi, Architectural Historian, Leslie A.G. Dill, Historic Architect, and Charlene Duval, Public Historian. Our firm is well versed in the evaluation of local historic resources. About 10 years ago, we assisted the County Planning Office in updating to current standards nearly 200 listed properties on the Santa Clara County Heritage Resources Inventory, and preparing the County’s first Historic Context Statement. Many of the inventoried properties are now designated landmarks. Since then we have also prepared County landmark nominations for Rhoades Ranch near Morgan Hill and the Bacigalupi House near Los Gatos. Concurrently during this same time period, within Santa Clara County we prepared National Register nominations for the Donner‐Houghton House and Earnest Renzel House in San Jose, Seven Springs Ranch in Cupertino, and the John Colpitts Ainsley House in Campbell. In San Jose and other local cities, we have prepared local landmark nominations for over 50 individual properties during the last decade, while providing documentation through survey work for more than 150 eligible properties, many now so designated. www.archivesandarchitecture.com As part of this investigation, Basim Jaber made available to us his extensive collection of resource material on the former Almaden Air Force Station. He also put us into contact with some of the preeminent military historians knowledgeable about Cold War military efforts and related technology. These included Mark Morgan, Phil Gioia, and David B. Leeson. Beth Wyman, Historian, provided peer review of our draft report and evaluation. Beth previously served on the County’s Historical Heritage Commission, and her valued input stems from a detailed knowledge of County history, including her work in updating the County’s Heritage Resources Inventory in the late 1990s. We have worked on a number of projects with strong public interest similar to that of the Radar Tower at Mount Umunhum. We approach our work in two steps: intensive background, and thorough investigation into the history and character of objects/structures/building/and places, necessary to adequately conduct proper evaluations for historical significance. Additionally, significance evaluations must bring into consideration an understanding of local values, as are often defined in General Plans and preservation ordinances. Heritage Commissions are an important step in ensuring that the work is inclusive, as they bring the broad areas of community interests and cultural values to the process of determining significance. Many would have us bury and forget the aspects of our collective past that represent the darker areas in American History. As a teenager growing up in Santa Clara Valley during the era of the Cold War, I have only now begun to truly understand the gravity of this conflict, and the risk to the continued existence of mankind that unfolded during the Cuban Missile Crisis and other critical moments during this period. Mount Umunhum and the Radar Tower is the most vivid reminder of that era, and today remains a beacon to local history, serving a purpose that has continued uninterrupted since the AN/FPS‐24 and its radar sail was decommissioned in 1980. It is my professional opinion as an Architectural Historian that the Mount Umunhum Radar Tower qualifies as a Santa Clara County Landmark, and as a life‐long resident and prior member of the Santa Clara County Historical Heritage Commission, I encourage the Commission to forward a recommendation to the Board of Supervisors that the structure be designated a Landmark under Ordinance NS‐1100.96. Franklin Maggi, Architectural Historian May 14, 2014 A R C H I V E S & A R C H I T E C T U R E HISTORICAL EVALUATION Mount Umunhum Radar Tower Sierra Azul Open Space Preserve Santa Clara County, California (APN #562-08-003) Prepared for: Santa Clara County Historical Heritage Commission C/o Michele Napier, Clerk County of Santa Clara 70 West Hedding Street, 7th Floor San José, CA 95110 Revised: 05.14.2014 ARCHIVES & ARCHITECTURE, LLC PO Box 1332 San José, CA 95109-1332 http://www.archivesandarchitecture.com Mount Umunhum Radar Tower HISTORICAL EVALUATION Table of Contents Table of Contents .............................................................................................................. 2 Introduction ....................................................................................................................... 3 Summary of Findings..................................................................................................... 5 Historical Information ........................................................................................................ 8 Cold War Context – Santa Clara County ........................................................................ 13 Evaluation for Significance .............................................................................................. 17 Policy and Regulatory Context .................................................................................... 17 Evaluation .................................................................................................................... 18 Qualifications of the Consultants..................................................................................... 20 Sources of Information .................................................................................................... 22 Attachments .................................................................................................................... 27 Cover image: Radar Tower, September 2013 (ARCHIVES & ARCHITECTURE photo) ARCHIVES & ARCHITECTURE 2 Mount Umunhum Radar Tower HISTORICAL EVALUATION Introduction At an elevation of 3,486 feet, Mount Umunhum is the fourth‐highest peak in the California Santa Cruz Mountains. Mount Umunhum is situated in Santa Clara County, southeast of the Town of Los Gatos and south of the City of San José. Today, the peak is recognized in Santa Clara Valley and beyond by the five‐story concrete radar tower building that sits atop the summit. The summit of Mount Umunhum is the site of the former Almaden Air Force Station, an early‐warning radar station built beginning in 1957, which operated from 1958 to 1980 during the Cold War. The mountain is also the site of the Bay Area’s NEXRAD Doppler weather radar (not located on the old Air Force Station property). Most of the mountain is now within the Sierra Azul Open Space Preserve, which is owned and managed by Midpeninsula Regional Open Space District. The de‐commissioned station was acquired in 1986 by Midpeninsula Regional Open Space District and today is abandoned and off‐limits to the general public. Public access is still in the planning stages. A project to demolish most of the buildings and structures (with the exception of the Radar Tower) began in 2013 and most of the buildings and structures have now been removed from the site as of Spring 2014. The location of Almaden Air Force Station (AFS) at the summit of Mount Umunhum was by design. Perched between Mill Valley AFS atop Mt. Tamalpais to the north, and Cambria AFS to the south, it filled an important gap in the Air Defense Command early warning and air defense coverage of the California coast. It also effectively doubled the Air Force radar coverage of the approaches to one of the predominant regions of the Pacific Rim, the San Francisco Bay Area complex of financial, governmental, military, industrial, and transportation centers. Figure 1 Radar Tower from Almaden Quicksilver County Park (2006) Archives & Architecture photo ARCHIVES & ARCHITECTURE 3 Mount Umunhum Radar Tower HISTORICAL EVALUATION Almaden AFS was officially established on July 24, 1957, when the 682nd Aircraft Control and Warning (AC&W) Squadron was assigned to the site.1 Almaden AFS became fully operational on March 21, 1958 as part of the San Francisco Air Defense Sector. It was known as Transmitter Site M‐96; AC&W Site M‐96; Call Mountain Radio Relay Annex; and eventually Almaden Air Force Station SAGE site Z‐96. When Almaden AFS became operational, it was equipped with an AN/FPS‐20 General Surveillance radar (built by Bendix beginning in 1956 for long‐range surveillance of up to 200 miles) and twin AN/FPS‐6 radars (built by General Electric beginning in the early 1950s as a long‐range height‐finding radar). The first AN/FPS‐6 radar was installed in 1957, and the second AN/FPS‐6 radar was installed as Building 107 in 1958 just prior to station operational status. The radar facilities were clustered at the east end of the complex on the highest point of the mountain immediately adjacent to the main Operations building 100. Building 100 contained the scope consoles, computer system, and all personnel related to the daily operations of the stations general surveillance. Building 102, the five‐story concrete tower that is the subject of this study, was under construction in 1959. An AN/FPS‐24 radar was installed in the building in 1961 and became operational later that year. Figure 2 ‐ Almaden Air Force Station crew (Jaber collection) See attachments for a detailed History and Context of 682nd Radar Squadron, prepared for this study by Mark Morgan, DAF. 1 ARCHIVES & ARCHITECTURE 4 Mount Umunhum Radar Tower HISTORICAL EVALUATION Summary of Findings Air Force facilities such as Almaden AFS were an essential aspect of the Cold War effort by the military in the 1950s and 1960s. Many residents of Santa Clara County played a pivotal role in national security during the Cold War, and Building 102, atop Mt. Umunhum at the now de‐commissioned Almaden AFS, remains today as an important and significant reminder of this effort. The contributions made by the local community help tell the story of modern Santa Clara County, and those who have lived in the valley these last 50 years continue to reflect upon this troubling period in national and local history. Many of the residents of the valley were employed by defense‐contractor corporations in the Bay Area (Santa Clara County, specifically), which all thrived under the security of a blanket of defense provided by Almaden AFS. While local residents who had a direct relationship with the operation can recall its legacy in detail, to the larger community, the Radar Tower known as Building 102 remains today as a reminder of the threat to their security brought on by the Cold War, and as such is the only means to physically convey this memory in the context of the county at large. When Almaden AFS closed, the remote nature of the site and lack of access caused the closure to go relatively unnoticed by the general public. One visible reminder remained, however‐‐the Radar Tower, which has now loomed over the valley for over half a century. Most locals can identify this peak as Mount Umunhum due to the presence of the tower, and can likely remind you that the word Umunhum derives from the Ohlone Indian name for “resting place of the hummingbird.” Figure 3 – Aerial view of Mount Umunhum (San Jose Mercury News) With a continuous strong visual presence, the tower continues to serve as a regional historic landmark and a cultural icon in Santa Clara County, and as such the tower qualifies for designation as a Santa Clara County Landmark pursuant to criteria defined under Division C17 of the Santa Clara County Code. ARCHIVES & ARCHITECTURE 5 Mount Umunhum Radar Tower HISTORICAL EVALUATION Area Map and Aerial USGS Los Gatos Quadrangle 7.5‐minute 1980 photo revised (partial) UTM: 10S 600847 4113038 Lat/Long: 37.15831 ‐121.86423 ARCHIVES & ARCHITECTURE 6 Mount Umunhum Radar Tower HISTORICAL EVALUATION Satellite View (ACME Mapper) ARCHIVES & ARCHITECTURE 7 Mount Umunhum Radar Tower HISTORICAL EVALUATION Historical Information Shortly after the end of World War II, it became apparent that tensions between the United States and the Soviet Union could not be contained, and they quickly spilled over into an all‐out global conflict. With the outbreak of the Cold War in the late 1940s, and then the Korean War in 1950, the U.S. Army and the U.S. Air Force quickly began reestablishing air defenses to protect the United States against manned bomber attacks from the Soviet Union and other enemies. Some air defense radar sites that were used in World War II were reactivated, and many new sites were established, creating a network of bases and warning systems along the United States borders. The west coast was no exception to this, and California, more specifically the Bay Area, was a part of this network of defense. One of 28 stations built as part of the second segment of the Air Defense Command permanent radar network, Mount Umunhum’s Almaden Air Force Station was a U.S. Air Force early warning radar base that operated from 1958 to 1980. The base was constructed as part of the North American Aerospace Defense Command (NORAD) to keep watch over Northern California’s airspace during the Cold War. To develop the site, the U.S. Air Force acquired, between 1957 and 1962, a total of 118.36 acres from several private individuals and the San Jose Water Works (SJWW), a local public utility company. The flag‐raising ceremony held by personnel of the 682nd Aircraft Control and Warning Squadron on July 24, 1957 marked the initial operating capability of the air force station; the entire squadron formally transferred operations from Hamilton Air Force Base (AFB) in San Rafael to Almaden AFS on October 7, 1957. Initially equipped with the AN/FPS‐20 search radar built by Bendix, and AN/FPS‐6 height‐finder radars, the station quickly became operational in the manual air defense network, reporting to the 28th Air Division (Defense) at Hamilton AFB. The radar facilities were clustered at the east end of the complex on the highest point of the mountain. These buildings included the radar towers, operations building, underground bomb shelter, and power production generator buildings. ARCHIVES & ARCHITECTURE Figure 4 ‐ 1964 Radar Tower with airman in foreground (Jaber collection) 8 Mount Umunhum Radar Tower HISTORICAL EVALUATION As part of the conversion to the Semi‐Automatic Ground Environment (SAGE) network, the site subsequently gained an upgraded height‐finder radar, an AN/FPS‐90, as well as an upgraded Ground‐Air Transmit‐Receive (GATR) facility, in 1958 and 1962 respectively. The conversion to SAGE resulted in the squadron’s reassignment to the San Francisco Air Defense Sector, which operated from SAGE Direction Center DC‐18 at Beale AFB, California, which is located 40 miles north of Sacramento. The AN/FPS‐20 radar was replaced by a massive 85.5 ton AN/FPS‐24 search radar (manufactured by General Electric) atop Building 102, the five‐story concrete tower constructed between 1959 and 1961, visible from the valley floor, known today simply as the Mount Umunhum Radar Tower. The site served as the second production AN/FPS‐24 in Air Defense Command, following a similar installation at Point Arena AFS (located 150 miles north of San Francisco near California’s coastline), and was one of seven constructed of masonry and reinforced concrete. It functioned as a frequency diverse (FD) long‐ range search radar designed to Figure 5 ‐ 1962; AN/FPS‐24 radar and tower (Jaber collection) operate in the Very High Frequency (VHF) and was the second of only 12 production models built between 1958 and 1962. The AN/FPS‐24 radars at Point Arena AFS and Almaden AFS were constructed at nearly the same time, but due to the funding cutbacks, Almaden’s was completed later. Due to the remote location of the initial production AN/FPS‐24 at Point Arena AFS, the Air Force (in conjunction with General Electric) decided to use the Almaden AFS FPS‐24 radar for the initial 1,000‐hour test run. This initial testing was vital to the benchmarking of the elaborate AN/FPS‐24 radar to be used for all subsequent installations, and effectively rendered the Almaden AN/FPS‐24 radar as the “gold standard” for this model. The AN/FPS‐24 radar had a 250‐mile range designed to detect incoming hostile aircraft, and was considerably stronger than the 200‐mile range of the Air Force radars at Mill ARCHIVES & ARCHITECTURE 9 Mount Umunhum Radar Tower HISTORICAL EVALUATION Valley and Cambria. Manned by personnel of the 682nd Squadron, the big radar maintained a constant, unblinking watch on the western and southwestern approaches to San Francisco Bay for over two decades. Building 102 was designed and engineered by the firm of Burns and Roe and the site was engineered by Indenco Engineers of San Leandro, California.2 For detailed information on contents of each floor of the AN/FPS‐24 radar tower, see the attachments section of this report. Previously, the station operated a Ground‐to‐Air Transmitter‐Receiver (GATR) atop the summit of Mount Umunhum until the completion of the AN/FPS‐24 radar. To eliminate radio frequency interference from the AN/FPS‐24 radar, the GATR was then moved one mile west to the summit of nearby Mount Thayer (elevation 3,483 feet). In 1961, Almaden AFS joined the SAGE system, feeding computer data to a data center at Beale AFB, California. The SAGE Direction Center at Beale AFB was known as DC‐18. After joining SAGE, the squadron was re‐designated as the ʺ682nd Radar Squadron (SAGE).ʺ In 1963, the SAGE site information was switched to DC‐17 at Norton AFB, located near San Bernardino. That same year on July 31, 1963, the Mount Umunhum site was re‐designated as NORAD ID Z‐96. Figure 6 ‐ 1978 Bicentennial logo and Squadron welcome message on Operations Building (Jaber collection) The engineering firm of Burns and Roe was first founded in New York in 1932 by Ralph C. Roe and Allen E. Burns. By the mid‐1950s, Burns and Roe was heavily involved with the defense industry in the United States as the Cold War progressed. The firm was at the forefront of the design of the developing missile defense system, and the government installations that supported it. Burns and Roe became experts in defense systems, and worked on several projects during this period, including the Nike‐Zeus Missile Tracking Radar Project, the “Bull Goose” Missile Shelter Project, and the Semi‐Automated Ground Environment (SAGE) Systems of Air Defense Network. 2 ARCHIVES & ARCHITECTURE 10 Mount Umunhum Radar Tower HISTORICAL EVALUATION In 1968, as the result of defense budget cuts and a reduction in the Department of Defense’s emphasis on protection of the country against Soviet‐manned bombers, Air Defense Command (ADC) started deactivating its remaining long‐range radar sites in the interior of the country. In the general vicinity of California, the stations included the 658th Radar Squadron (SAGE), Winnemucca AFS, Nevada, and the 821st RADS (SAGE), Figure 7 ‐ 1979 birdʹs eye view of Mount Umunhum summit Baker AFS, Oregon. On June 18, 1968, one of the California coastal sites shut down: the 666th RADS (SAGE) at Lompoc AFS. By this point, Air Defense Command had also deactivated several interior SAGE direction centers, including the San Francisco ADC at Beale, which was deactivated on August 1, 1963. Directed by the Department of Defense partly in recognition of the increased Soviet intercontinental ballistic missile threat and partly due to their proximity to major target areas, the decision to deactivate selected Defense Commands resulted in the loss of six centers at locations around the country. In their stead, the Air Force developed the Back‐Up Interceptor Control system (BUIC), with widely‐separated long‐range radar sites serving as alternate direction centers in the event of an attack on the continental United States. As noted by historian Dr. Karen Weitze, “ADC command and control centers were important targets for a Soviet strike: the more of them there were, and the more widely they were dispersed, the more likely that the air defense system could function if partially destroyed.” BUIC I, deployed during the early 1960s, was the manual system; BUIC II was the first of two SAGE‐capable systems which went operational in 1966 at 14 locations, including Almaden AFS. As part of the conversion, the long‐range radar operations building at the station was enlarged to accommodate additional computers and display equipment as well as a command and control room. The buildings also received additional radio frequency and blast hardening in the form of a two‐foot‐thick outer shell of reinforced concrete with embedded radio frequency (RF) shields. As a BUIC II site, Almaden backstopped the 26th Air Division Air Defense Control Center (ADCC) at Adair AFS near Corvallis, Oregon. After suspension of BUIC II operations in 1968, the improved BUIC III sites at Mount Laguna AFS (east of San Diego, 751st Air Defense Group), Fallon AFS, Nevada (858th ADG) and Kingsley Field, Klamath Falls, ARCHIVES & ARCHITECTURE 11 HISTORICAL EVALUATION Oregon (827th ADG) assumed backup command and control responsibilities for the West Coast, and Almaden reverted to an air defense detection and surveillance mission. In 1979, Almaden AFS came under Tactical Air Command (TAC) jurisdiction with the inactivation of Aerospace Defense Command and the creation of Air Defense‐Tactical Air Command (ADTAC). On June 30, 1980, the 682nd Radar Squadron was rendered inactive at Almaden AFS. Its “retirement” left ADTAC with only four Air Force‐manned and operated long‐range radar stations guarding the Pacific Coast. From the north, they were the 758th RADS, Makah AFS, Washington; 777th RADS, Klamath AFS, California; 666th RADS, Mill Valley AFS, California; and 775th RADS, Cambria AFS, California. Air Force personnel manned height‐finder radar detachments at several Federal Aviation Administration (FAA) radar sites up and down the coast. The AN/FPS‐24 radar antenna “sail” was removed in June 1980 with the height‐finder radars at Almaden AFS removed about the same time. Figure 8 ‐ 1980 removal of sail (Jaber collection) ARCHIVES & ARCHITECTURE 12 HISTORICAL EVALUATION Cold War Context – Santa Clara County Following World War II, the United States Air Defense Command (ADC) began dismantling the existing air defense radar, filter (fighter direction) centers and HF/DF (high‐frequency/direction finder) sites around the perimeter of the country network that had been put in place during the war. This deactivation, however, was short‐lived. As the U.S.S.R. consolidated its control over the states of the Eastern Bloc, the United States began a strategy of global containment to challenge Soviet power, extending military and financial aid to the countries of Western Europe and creating the NATO alliance. In response to increasingly heightened international tensionschief among them a Soviet coup in Czechoslovakia in February 1948, followed by the Berlin Blockade in April of that same yearthe newly independent U.S. Air Force directed ADC to reverse the shutdown of the radar and command and control sites and to start manning them again. ADC immediately responded to this order on both the west and the east coasts of the country. Almaden Air Force Station was the last of Air Defense Command’s long‐ range radar sites to go “on watch” in California and would serve as one of last Air Force‐manned and operated radar sites in the Golden State. The radar sites located along the United States west coast provided peace and security to the American population at a time in history when life was anything but peaceful. It is difficult for those who did not live through the Cold War to understand the immense psychological effect the constant threat of possible nuclear attack had on all aspects of society, from the economy, to politics, and especially to the technological development that occurred in the United States during this time period. Until the development and deployment of reliable intercontinental ballistic missiles (ICBMs) and submarine‐ launched ballistic missiles (SLBMs), the main threat of foreign attack on the United States was from the air, particularly by long‐range Soviet aircraft carrying nuclear weapons. This made the early‐detection radar systems crucial to the nation’s defense strategy. Silicon Valley’s initial development beginning in the early part of the twentieth century is a legacy that comes from a combination of defense‐funded companies and a university that focused on early radio and then radar technology during two world wars and the Cold War conflicts. Historians trace the Valley’s roots back over 100 years, to the first decade of the twentieth century, when the electrification of California was in full swing and radio communications technology, controlled by Marconi patents, was in its infancy. The shipping fleets and navies of the world were among the first to fund radio communications. Since the San Francisco Bay Area was home to major Pacific shipping companies, the need for affordable and independent radio systems sparked the founding of local radio manufacturers. Radio and vacuum tubes, and then the defense radar of the World War II and Cold War eras, set the stage for the emergence of Stanford ARCHIVES & ARCHITECTURE 13 HISTORICAL EVALUATION University, the venture capital business and the successive waves of semiconductor, computer, network, cell‐phone and software companies to form a ground zero for technological development unmatched anywhere else in the world. The Bay Area has long been a major site of military research and technology, originating with the U.S. Navy at the turn of the century. In 1909, Charles Herrold started the first radio station in the United States with regularly scheduled programming in San José. Later that year, Stanford University graduate Cyril Elwell purchased the U.S. patents for Poulsen arc radio transmission technology and founded the Federal Telegraph Corporation (FTC) in Palo Alto. Over the next decade, the FTC created the worldʹs first global radio communication system, and signed a contract with the Navy in 1912. In 1933, Air Base Sunnyvale, California, was commissioned by the United States Government for use as a Naval Air Station (NAS) to house the airship USS Macon in Hangar One. The station was renamed NAS Moffett Field, and between 1933 and 1947, U.S. Navy blimps were based there. A number of technology firms had set up shop in the area around Moffett Field to serve the Navy. When the Navy gave up its airship ambitions and moved most of its west coast operations to San Diego, the National Advisory Committee for Aeronautics (NACA, forerunner of NASA) took over portions of Moffett Field for aeronautics research. Many of the original companies stayed, while new ones moved in. The immediate area was soon filled with aerospace firms, such as Lockheed. Lee de Forest, an American inventor with over 180 patents to his credit and the self‐ proclaimed ʺFather of Radioʺ, invented the Audion in 1906, the first triode vacuum tube and the first electrical device that could amplify a weak electrical signal and make it stronger. The Audion, and vacuum tubes developed from it, founded the field of electronics and dominated it for 40 years, making radio broadcasting, television, and long‐distance telephone service possible, among many other applications. For this reason De Forest has been credited as one of the founders of the ʺelectronic age.ʺ He is also credited with one of the principal inventions that brought sound to motion pictures. De Forest came to San Francisco in 1910, and worked for the Federal Telegraph Company, which began developing the first global radio communications system in 1912. California Historical Landmark No. 836 is a bronze plaque at the eastern corner of Channing Street and Emerson Avenue in Palo Alto, California, which memorializes the Electronics Research Laboratory at that location and De Forest for the invention of the three‐element radio vacuum tube. Stanford University in Palo Alto, California, its affiliates, and its graduates have played a major role in the development of military research and technology. From its founding in the 1890s, Stanford Universityʹs leaders saw its mission as service to the West and shaped the school accordingly. During the 1940s and 1950s, Frederick Terman (often called the “father of Silicon Valley”), Stanfordʹs Dean of Engineering and Provost, encouraged faculty and graduates ARCHIVES & ARCHITECTURE 14 HISTORICAL EVALUATION to start their own companies. Terman is credited with nurturing companies like Hewlett‐Packard, Varian Associates, and other high‐tech firms, until what would become Silicon Valley grew up around the Stanford campus. After World War II, universities were experiencing enormous demand due to returning students. To address the financial demands of Stanfordʹs growth requirements, and to provide local employment opportunities for graduating students, Terman proposed the leasing of Stanfordʹs lands for use as an office park, named the Stanford Industrial Park (later Stanford Research Park). Leases were limited to high technology companies. The Park’s first tenant was Varian Associates, founded by Stanford alumni in the 1930s to build military radar components. Between 1955 and 1988, solid state technology research and development at Stanford University followed three waves of industrial innovation made possible by support from private corporations, mainly Bell Telephone Laboratories, Shockley Semiconductor, Fairchild Semiconductor, and Xerox PARC. In 1964, Terman had brought William Shockley to Palo Alto to form a commercial venture in semiconductors. Unlike many other researchers who used germanium as the semiconductor material, Shockley believed that silicon was the better material for making transistors. Shockley intended to replace the current transistor with a new three‐element design (today known as the Shockley diode), but the design was considerably more difficult to build than the ʺsimpleʺ transistor. In 1957, Shockley decided to end research on the silicon transistor. Eight engineers left the company to form Fairchild Semiconductor; two of the original employees of Fairchild Semiconductor, Robert Noyce and Gordon Moore, would go on to found Intel. In 1957, Dean Watkins and R. H. Johnson had co‐founded Watkins‐Johnson, with a venture capital investment from Tommy Davis at Kern County Land Development Corporation. Watkins had been a research leader at Stanford University’s Electronic Laboratory, while Johnson was the head of Hughes Aircraft’s microwave tube department. Watkins‐Johnson was the first defense‐oriented venture capital investment, and set the bar for many more to follow, as technology corporations with defense contracts became the basis for the Bay Area’s burgeoning aerospace‐defense sector during the Cold War era. The growing list of other defense firms in the Valley included Eitel‐McCullough, Varian, and Litton Industries. Others would soon join them. By the early 1960s, one‐third of the nation’s defense microwave business was located in the Santa Clara Valley. Watkins‐Johnson became the cornerstone for the immense network of venture capital, human intellectual potential, and entrepreneurial drive that later become known as Silicon Valley (even though the firm was based on microwave technology). The growth of the venture capital industry was fueled by the emergence of the independent investment firms on Sand Hill Road in Menlo Park, California, beginning with Kleiner Perkins Caufield & Byers and Sequoia Capital in 1972. These and other venture capital firms would have access to the many semiconductor companies based in ARCHIVES & ARCHITECTURE 15 HISTORICAL EVALUATION the Santa Clara Valley as well as early computer firms using their devices and programming and service companies. In the 1970s and 1980s, the majority of technology and products developed by firms in Silicon Valley were incorporated in some form or another into defense systems designed to protect the United States from the Soviet threat. The protected environment located in the shadow of Mout Umunhum, made possible by Almaden Air Force Station, in which this development and growth could take place, was a critical necessity to the development of Silicon Valley. Figure 9 1968 view of Mt. Umunhum from Almaden Valley (Alexander Dewey) ARCHIVES & ARCHITECTURE 16 HISTORICAL EVALUATION Evaluation for Significance Policy and Regulatory Context County of Santa Clara The County of Santa Clara, through its General Plan, considers heritage resources as those particular types of resources, both natural and man‐made, which due to their vulnerability or irreplaceable nature deserve special protection if they are to be preserved for current and future generations. Heritage resources are considered important for a variety of reasons, including potential scientific value, cultural and historical value, and “place” value, in addition to their irreplaceability. Knowledge of the natural world, understanding of cultural origins, continuity with the past, and the sense of place that defines us and distinguishes Santa Clara County from all other places are all enhanced through heritage resource preservation. In the face of increasing homogenization, urbanization, and anonymity of American culture and places, resources unique to each region and locality become even more significant. More than curiosities, landmarks by which to navigate, or tourist attractions, heritage resources should be considered the birthright of successive generations of residents. If preserved and integrated with the new, our historic buildings, groves of trees, and other resources immeasurably enrich the experience of urban and rural landscapes. Rehabilitation and restoration for new uses or for commemoration, especially within older, central urban communities can also help revitalize economies and reverse urban decline in ways urban “renewal” programs of the recent past often failed to do. Cultural heritage resource protection consists of three basic strategies in the County of Santa Clara General Plan; Inventory and Evaluate Heritage Resources, Prevent or Minimize Adverse Impacts on Heritage Resources, and Restore, Enhance and Commemorate Resources. In keeping with the General Plan policies on cultural resources, the County of Santa Clara has adopted a Historical Preservation Ordinance (Division C17 of the Santa Clara County Code, ordinance No. NS‐1100.96, 10‐17‐06). The purpose of the ordinance is for the preservation, protection, enhancement, and perpetuation of resources of architectural, historical, and cultural merit within Santa Clara County and to benefit the social and cultural enrichment, and general welfare of the people. The County mains a Heritage Resource Inventory and list of designated Landmarks. Historic resources are evaluated according to criteria in Article II of the Division C17, Chapter 3.50 of the Zoning Ordinance, or division C16 of the County Code. The Board of Supervisors has the authority to designate as Landmarks, properties which meet the following criteria: A. Fifty years or older. If less than 50 years old, sufficient time must have passed to obtain a scholarly perspective on the events or individuals associated with the historic resource and/or the historic resource is a distinctive or important example of its type or style; and ARCHIVES & ARCHITECTURE 17 HISTORICAL EVALUATION B. Retains historic integrity. California Code of Regulations Section 4852(c) addresses the issue of “integrity” which is necessary for eligibility for the California Register. Integrity is defined as “the authenticity of an historical resource’s physical identity evidenced by the survival of characteristics that existed during the resource’s period of significance.” Section 4852(c) provides that historical resources eligible for listing in the California Register must meet one of the criteria for significance defined by 4852(b)(1 through 4), and retain enough of their historic character of appearance to be recognizable as historical resources and to convey the reasons for their significance. Integrity is evaluated with regard to the retention of location, design, setting, materials, workmanship, feeling, and association. It must also be judged with reference to the particular criteria under which a resource is proposed for eligibility. Alterations over time to a resource or historic changes in its use may themselves have historical, cultural, or architectural significance; and C. Meets one or more of the following criteria of significance: 1. Associated with events that have made a significant contribution to the broad patterns of local or regional history, or the cultural heritage of California or the United States; 2. Associated with the lives of persons important to local, California or national history; 3. Embodies the distinctive characteristics of a type, period, region, or method of construction, or represents the work of a master or possesses high artistic values; or 4. Yielded or has the potential to yield information important to the pre‐history or history of the local area, California, or the nation. Evaluation The intent of this evaluation is to determine the eligibility of the Mount Umunhum tower for designation as a County of Santa Clara Landmark. Under Division C17 of the Santa Clara County Code, the Board of Supervisors has adopted a Historic Preservation Ordinance that regulates the identification, designation, and treatment of historic properties. The Ordinance is for the preservation, protection, enhancement, and perpetuation of resources of architectural, historical, and cultural merit within Santa Clara County and to benefit the social and cultural enrichment, and general welfare of the people. The Board of Supervisors may designate those historic resources as ʺlandmarksʺ which meet the following designation criteria: A. Fifty years or older. If less than 50 years old, sufficient time must have passed to obtain a scholarly perspective on the events or individuals associated with the historic resource and/or ARCHIVES & ARCHITECTURE 18 HISTORICAL EVALUATION the historic resource is a distinctive or important example of its type or style; and of the local area, California, or the nation. The Mt. Umunhum Radar Tower was constructed beginning in 1959, and meets the minimum 50 years requirement. B. Retains historic integrity. If a historic resource was moved to prevent demolition at its former location, it may still be considered eligible if the new location is compatible with the original character of the property; The Mount Umunhum Radar Tower possesses integrity of location and setting. The building has not been moved, although the surrounding buildings are in the process of being demolished at the time of the beginning of this study. Integrity of design, materials, workmanship, feeling, and association had been compromised somewhat because the radar sail and related equipment on the roof has long been removed, and technical machinery to operate the radar no longer exists. Like all decommissioned radar installations in the United States, the radar equipment was removed from the site following decommission, but the building itself retains its original appearance. The structure remains an important representation of the historic background of the former base, and has sufficient integrity to convey its history. Meets one or more of the following criteria of significance: 1. Associated with events that have made a significant contribution to the broad patterns of local or regional history, or the cultural heritage of California or the United States; The Mount Umunhum Radar Tower is individually significant at the local level within the former Almaden Air Force Station under Criterion 1 as a prominent example of radar operation at the site and within the Santa Clara County itself. Though not the first or only radar erected at the Almaden Air Force Station, it best represents the overall mission and purpose of Almaden AFS, and has served as a visual symbol of an important era in county history to the county due to its prominent perch above the valley. Of all the remaining artifacts of the Cold War era from 1959 to 1980, the Radar Tower at Mount Umunhum remains the most visual and memorable icon, easily recognizable to the entire population of Santa Clara County. It is of historic significance within the county due to its prominent, distinctive image, its important associations, and the expansive understanding of what it represents to the local population. The property meets Criterion 1 under the County’s ordinance for landmark designation. 2. Associated with the lives of persons important to local, California or national history; The Mount Umunhum Radar Tower is not individually significant under Criterion 2 because it is not associated with the lives of individual persons significant in our past. No individuals were identified as being instrumental to the function of the ARCHIVES & ARCHITECTURE 19 HISTORICAL EVALUATION radar system at Almaden AFS. The property does not meet Criterion 2 under the County’s ordinance for landmark designation. 3. Embodies the distinctive characteristics of a type, period, region, or method of construction, or represents the work of a master or possesses high artistic values; The Mount Umunhum Radar Tower is individually significant locally under Criterion 3 as a unique concrete radar tower in Santa Clara County, that once supported the highest‐powered radar antenna at the now decommissioned Almaden Air Force Station site. The Radar Tower is a distinctive architectural specimen, both for its unique construction as a military radar tower during the Cold War, as well as its prominent location high about the valley floor in Santa Clara County. The radar tower is a distinguished and locally well‐known example of utilitarian military architecture. It is a distinctive local monument of this type, associated directly with an important period in military history. The property meets Criterion 3 under the County’s ordinance for landmark designation. 4. Yielded or has the potential to yield information important to the pre‐history or history. The pre‐history of the site was not investigated for its potential to yield important information. The site of the Mount Umunhum Radar Tower was subject to a different process for eligibility under National Register Criterion D (Information Potential) under Section 106 of the National Historic Preservation Act, and is not a part of this evaluation. The evaluation of potential archeological resources is beyond the scope of this report. Qualifications of the Consultants Franklin Maggi, Architectural Historian Franklin Maggi is the Managing Partner for ARCHIVES & ARCHITECTURE. As a preservation planner and historian, he has prepared intensive‐level project assessments involving historic resources for a large and diverse range of properties in the region. His early experience as an urban planner provided him with a background in regulatory procedures and entitlements. As the lead historian on the Santa Clara County Inventory Update project in 2004, prepared by Archives & Architecture for the County Planning Office, he updated and re‐evaluated a broad range of historic resources in the unincorporated areas of the county, and was the key author on the Santa Clara Historic Context Statement, adopted by the Board of Supervisors in 2012. In the 1990s, Franklin Maggi served the County as a Historical Heritage Commissioner, as well as full‐filling two terms on the San Jose Historic Landmarks Commission. He presently is a board member of the Sourisseau Academy for State and Local History, SJSU. ARCHIVES & ARCHITECTURE 20 HISTORICAL EVALUATION Franklin Maggi has a professional degree in Architecture with an area of concentration in Architectural History from the University of California, Berkeley. He is listed with California Historical Resources Information System (CHRIS) as Architectural Historian, and meets the Secretary of the Interior’s Standards within his profession. Sarah Winder, Historian Sarah Winder is a staff historian for ARCHIVES & ARCHITECTURE. Working with the firm since graduating from San Jose State University, she has prepared local landmark and National Register nominations such as the large multi‐thematic cultural landscape known as Rhoades Ranch, and prepared historical reports for properties within most of the cities in Santa Clara County. She prepared the historical narrative for the 3,000 acre Kaiser Permanente Quarry, and has conducted research for a number of projects for special purpose agencies such as Caltrans and the Santa Clara Valley Water District. Sarah Winder has a Master of Arts in History from San Jose State University and a Bachelor of Arts in History and Anthropology from the University of Colorado, Boulder. Her coursework focused on Modern European history and the Cold War. She is listed with CHRIS as Historian, and meets the Secretary of the Interior’s Standards within her profession. In addition to the two staff members of Archives & Architecture, LLC, Mark Morgan, Phil Gioia, David Leeson, and Basim Jaber contributed to the content of this report. Mark Morgan’s biography is not included, but he is currently a civilian Air Force historian and aviation writer with 30+ years experience who recently published Rings of Supersonic Steel: An Introduction & Site Guide Air Defenses of the United States Army 1950‐ 1979, 2010. He was formally a historian for the Western Air Defense Sector, whose operational area incorporates California. Phil Gioia, Military Historian Contributing to this report was Phil Gioia, General Partner of Pathfinder Partners LLC. Gioia served ten years active military service as a Regular Army officer in Infantry, Airborne, Ranger, and Pathfinder, including two combat Infantry command tours in Vietnam in the 505th Parachute Infantry Regiment of 82d Airborne Division, and 5th Cavalry Regiment of First Cavalry Division (Airmobile). Following Vietnam, Mr. Gioia took the Advanced Course at the Armor School and graduate work at the School of Foreign Service, Georgetown University, and served within the Sixth Army General Staff at the Presidio of San Francisco. Following graduate work at the Stanford University School of Business, he spent thirty‐three years in technology investment, management, and entrepreneurship, in and around Silicon Valley. He is founder and CEO of two technology companies, and is co‐founder and Partner of Pathfinder Partners at the Presidio of San Francisco, California, providing directed advisory services to clients in the defense and national security sectors. Phil Gioia is a noted Military Historian; a frequent commentator on the History and Military Channels, and a writer on topics of military history. ARCHIVES & ARCHITECTURE 21 HISTORICAL EVALUATION Dave Leeson David B. Leeson has been Professor of Electrical Engineering of Stanford University, Palo Alto, California since 1994. He holds a Bachelor of Science from California Institute of Technology, a Master of Science from Massachusetts Institute of Technology (NSF Fellow) and Ph.D. from Stanford University (Hughes Fellow). He served as Chief Executive Officer and Founding Chairman of California Microwave, Inc. from1968 to 1993, and currently serves as Executive Officer of Leeson Foundation while also owning a communications tower business. His Specific Research Interests include satellite and microwave communications, ionospheric propagation, personal wireless communications, organizational life cycles and the dependence of success upon nonlinear and second‐order phenomena. Corporate directorships include that of Morphics Technology Inc., Stanford Telecommunications, Inc., Advanced Radio Cells, Inc. and Reflectivity, Inc. Public service positions have included being a member of IEEE 802.11 (wireless data networking standards), Governor of Electronic Industries Alliance (EIA/TIA), and Director of American Electronics Association (AEA). He has served as Founding Chairman of WINForum (personal wireless industry association) since 1993, and is an IEEE Life Fellow, receiving the IEEE Cady Award, Stanford Graduate School of Business Entrepreneur of the Year, and MIT Distinguished Alumnus Award. Dave Leeson is author of IEEE papers on nonlinear frequency multipliers, radar, oscillator stability (“Leesonʹs model of oscillator noise“), and a book on Yagi antennas. Basim Jaber A lifelong South Bay native and freelance photographer, Basim Jaber has researched the history and geography of Mt. Umunhum and the Almaden Air Force Station since 2006. He has organized and hosted several veteransʹ reunions for the USAF 682nd Radar Squadron who manned the radar station atop Mt. Umunhum between 1957 and 1980. He continues to archive historic images and artifacts from Almaden Air Force Station to help preserve the memories and history of this Bay Area Cold War relic. His relationship with over 200 veterans and dependents who lived and served on the site has earned him status as their official historian and archivist. Basim has assisted several media agencies in producing newspaper, TV, and web media coverage of the site and its fascinating past. These include CBS‐5 KPIX ʺEye on the Bayʺ, NBC KRON‐4 News, San Jose Mercury News, Patch.com online, KQED ʺQUESTʺ TV, and Almaden Times Weekly. His photo documentary work of the entire site has proven invaluable to preserving the history and memories of Almaden Air Force Station (see http://www.almadenafs.org ). Basim also serves as a board director on the Umunhum Conservancy, a non‐profit organization with a mission to save and preserve the iconic radar tower atop Mt. Umunhum (see http://www.umunhumconservancy.org ). ARCHIVES & ARCHITECTURE 22 HISTORICAL EVALUATION Figure 11 ‐ 2008 Reunion (Jaber collection) ARCHIVES & ARCHITECTURE 23 HISTORICAL EVALUATION Sources of Information Archives & Architecture, LLC. County of Santa Clara Historic Context Statement. County of Santa Clara, Department of Planning and Development, 2012. California (State of), Public Resources Code, Section 21000, et. seq. and The California Environmental Quality Act (CEQA) Guidelines, California Administrative Code, Section 15000, et. seq., 1970 (as amended). California (State of), Department of Parks and Recreation, Office of Historic Preservation (CAL/OHP). California Points of Historical Interest. Sacramento: California Department of Parks and Recreation, 1992. ‐‐‐‐‐. Instructions for Recording Historic Resources, 1995. ‐‐‐‐‐. Title 14 Chapter 11.5. Regulations for California Register of Historical Resources, 1997. ‐‐‐‐‐. Directory of Properties (Santa Clara County) in the Historic Property Data File, 2013. (Includes National Register of Historic Places status codes, California Historical Landmarks and California Points of Historical Interest listings, etc.) ‐‐‐‐‐. Technical Assistance Series #6: California Register and National Register: A Comparison (for purposes of determining eligibility for the California Register), 2002. ‐‐‐‐‐. Title 14 Chapter 11.5. Regulations for California Register of Historical Resources. Effective January 1, 1998. Cornett, Lloyd H., Jr. and Mildred W. Johnson. A Handbook of Aerospace Defense Organization, 1946‐1980. Peterson AFB, Colorado: Office of History, Aerospace Defense Center, 1980. Department of Defense. Coming in from the Cold: Military Heritage in the Cold War, Report on f the Department of Defense Legacy Cold War Project. Washington D.C. publisher GPO, 1994. Hylkema, Mark G. Negative Archaeological Survey Report (NASR): A Finding of No Effect to Archaeological Resources, Mount Umunhum Restoration and Public Access Project. Mid‐ Peninsula Regional Open Space District, 2011. Gregory, Carrie, and Martyn Tagg. Recording the Cold War: Identifying and Collecting Cold War Resource Data on Military Installations. Department of Defense Legacy Resource Management Project No. 07‐285, 2008. ARCHIVES & ARCHITECTURE 24 HISTORICAL EVALUATION Gudde, Erwin G. California Place Names: The Origin and Etymology of Current Geographical Names. Berkeley: University of California Press, 1965. Jackson, J. B. The Necessity for Ruins and Other Topics. Amherst: University of Massachusetts, 1980. Leeson, David. “The Role of Defense Funding in the Making of Silicon Valley.” Palo Alto: David Leeson, 2014. Leslie, Stuart W. “How the West Was Won: The Military and the Making of Silicon Valley,” in Technological Competitiveness and Historical Perspectives on the Electrical, Electronics, and Computer Industries, edited by William Aspray. New York: IEEE Press, 1993. Lewis, Karen, and Paul Boyer, Joseph S. Murphy, Lori E. Rhodes, and Katherine J. Roxlau. A Systematic Study of Air Combat Command Cold War Material Culture. Volume I: Historic Context and Methodology for Assessment. Mariah Associates, Inc., Fort Worth, Texas, 1995. Page & Turnbull, Inc. Final Historic Resource Study of Former Almaden Air Force Station, Mt. Umunhum, Santa Clara County, CA. Mid‐Peninsula Regional Open Space District, 2010. Including DPR523 recording of Building 102: Radar Tower FPS‐24, 9/011. Salmon, John S. Protecting America: Cold War Defensive Sites, A National Historic Landmark Theme Study. National Historic Landmarks Program, Cultural Resources, National Park Service, U.S. Department of the Interior, Washington D.C., 2011. Shiman, Philip. Forging the Sword: Defense Production in the Cold War. U.S. Army Corps of Engineers, Engineering Research Laboratory, Special Report 97/77, sponsored by U.S. Air Force Air Combat Command and the Department of Defense Legacy Program, 1995. United States Air Force. Interim Guidance: Treatment of Cold War Historic Properties of U.S. Air Force Installations. On file at Department of Defense Legacy Program Office, Washington, D.C., 1993. Williams, James C. The Rise of Silicon Valley. Cupertino: California History Center Foundation, 1993. Winkler, David F. Searching the Skies: The Legacy of the United States Cold War Defense Radar Program. Champaign, IL: United States Air Force Headquarters Air Combat Command, 1997. ARCHIVES & ARCHITECTURE 25 HISTORICAL EVALUATION Interview Mark, Morgan. Telephone interview with Franklin Maggi and Basim Jaber, August 22, 2013. Websites http://www.fas.org/nuke/guide/usa/airdef/an‐fps‐24.htm (website accessed on October 30, 2013) http://www.radomes.org/museum/equip/radarequip.php?link=fps‐24.html (website accessed on October 30, 2013) http://www.radomes.org/museum/equip/fps‐20.html (website accessed on November 4, 2013) http://www.fas.org/nuke/guide/usa/airdef/an‐fps‐20.htm (website accessed on October 30, 2013) http://radomes.org/museum/equip/fps‐6.html (website accessed on November 4, 2013) http://www.fas.org/nuke/guide/usa/airdef/an‐fps‐6.htm (website accessed on October 30, 2013) http://www.radomes.org/museum/data/newsletters/AlmadenAFSCA2.jpg (website accessed on November 4, 2013) http://www.openspace.org/plans_projects/mt_umunhum.asp (website accessed on October 20, 2013) Figure 12 ‐ ʺRadar Sentinel Mount Umunhum overlooking Santa Clara Valley (1967 Pacific Telephone Directory) ARCHIVES & ARCHITECTURE 26 HISTORICAL EVALUATION Attachments History and Context of 682nd Radar Squadron, Mark Morgan, DAF. The Role of Defense Funding in the Making of Silicon Valley, D.B. Leeson DPR523 recording forms, including photographs. AN/FPS‐24 by Steve Weatherly posted on: http://www.radomes.org/museum/parsehtml.php?html=fps‐24.html&type=equip_html (This website contains extensive technical information on the AN/FPS‐24. For the purposes of this report, the information is referenced as an attachment, but must be viewed online by clicking the above hyperlink). ARCHIVES & ARCHITECTURE 27 HISTORICAL EVALUATION 682nd Radar Squadron The following History and Context of the 682nd Radar Squadron was provided by Mark Morgan, DAF, for use with this report. It is followed by his timeline for the Geiger Field/Kirtland AFB/Hamilton AFB/Almaden AFS (M-96/Z-96).Both have been reformatted for this evaluation. On 5 March 1946, former British Prime Minister Winston Spencer Churchill gave a speech at Westminster College in Fulton, Mo. During the course of his presentation he stated, “From Stettin in the Baltic to Trieste in the Adriatic, an iron curtain has descended across the Continent.” His use of the phrase “Iron Curtain” in describing the political and military situation in Europe marked the beginning of the Cold War. However, in the United States the Army Air Forces and War Department remained in their postWorld War II stand-down mode. Millions of men had demobilized at the end of the war and returned to their civilian lives while aircraft either went into storage, were scrapped or, in the case of the US Navy, were literally dumped over the sides of ships. Air defense? Not important; the United States had a monopoly on nuclear weapons and could handle all comers. On 21 March 1946, roughly two weeks after Churchill‘s speech at the small college town in America‘s heartland, the Army Air Forces established Strategic Air Command and tasked it with developing the nation‘s nuclear deterrent using a few groups of B-29 bombers. Concurrently, Tactical Air Command stood up at Langley Field, VA; six days later, Air Defense Command activated at Mitchel Field, Long Island, NY. Despite its “air defense” title, ADC‘s initial efforts revolved around closing down, packing and shipping out the remaining World War II-era radar, filter (fighter direction) centers and HF/DF (high-frequency/direction finder) sites around the perimeter of the country. In the Bay Area, these sites included WWII-era installations in Berkeley, Carmel, Half Moon Bay (two facilities), Mill Valley, Point Reyes, Olema, Gualala, Birds Landing and Point Montara. Along the same lines, upon activation ADC inherited operational responsibility for five numbered air forces. While First Air Force at Mitchel Field and Fourth Air Force in San Francisco for the most part continued their World War II mission of continental air defense, the others – Tenth AF, Brooks Field, Texas; Eleventh AF, Olmstead Field, Pa.; and Fourteenth AF, Orlando Army Air Base, Fla. – wholly busied themselves with training and administration of the air reserve components, including National Guard aviation. On 21 May 1947, Fourth Air Force activated the 636th Aircraft Control & Warning Squadron at Hamilton Field in Marine County, under assignment to the 505th Aircraft Control & Warning Group at McChord Field, Washington. The activation and assignment were described as temporary duty for “…the duration of time necessary to deactivate the former radar sites of the old San Francisco Control Group…” The squadron quickly closed out the remaining operations and equipment at Point Sur, Half Moon Bay, Point Reyes, Gualala and Birds Landing. On 21 December 1947, the squadron moved to Half Moon Bay Early Warning Station; by 31 March 1948, it had completed the dismantling of Olema, Gualala and Carmel. However, the circumstances driving Air Defense Command’s dismantling of the existing air defense network changed in March 1948. In response to heightened international tensions – chief among them a Soviet coup in Czechoslovakia in February, followed by the Berlin Blockade in April – the newly independent US Air Force directed Air Defense Command to reverse the shutdown of the radar and command and control sites and start manning them again. ADC immediately responded at the opposite ends of the country. At McChord Field, the 505th Aircraft Control & Warning Group (AC&WG) – the only air defense command and control organization in the entire western United States – received orders from Fourth Air Force to go on 24-hour operations with the intention of providing an “air defense radar net” in the Pacific Northwest (in other words, protect the Hanford Works). The group responded ARCHIVES & ARCHITECTURE 28 HISTORICAL EVALUATION quickly with the personnel it had and within a few days the 505th operated a limited surveillance capability from sites in Neah Bay, Spokane, Pasco, Seaside, Walla Walla and Portland manned by personnel of the 634th Air Control Squadron and 635th Aircraft Control & Warning Squadron. Concurrently the 505th AC&WG’s 636th and 637th Aircraft Control & Warning Squadrons took similar actions to guard the San Francisco Bay area and Los Angeles, respectively. By 2 August 1948, the regional Air Defense Direction Center at Silver Lake (Everett), Wash. was up and operating, with responsibility for operations along the entire Pacific coast. However, at the end of the year a major reorganization of air defense duties took place with the 1 December establishment of Continental Air Command (CONAC), which assumed jurisdiction of Air Defense Command’s air sovereignty and air reserve training missions. The detonation of the Soviet Union’s first atomic bomb on 29 August 1949 precipitated a massive expansion of US early warning and air defense infrastructure. The reorganization of the West Coast defensive laydown included the 1 December 1949 activation of the Western Air Defense Force (WADF) at Hamilton AFB, followed a week later by the activation of the 28th Air Division (Defense) and 542nd Aircraft Control and Warning Group at Hamilton AFB. The latter organization, tasked with both the command and control and early warning missions, assumed operational control of the newly activated 668th Aircraft Control & Warning Squadron at the Half Moon Bay Air Defense Control Center as well as the LASHUP program radar sites at Half Moon Bay and Mather AFB. Briefly, LASHUP, the first truly operational postwar air defense radar system, replaced the arguably stillborn SUPREMACY radar program of 1947. The program called for the emplacement of 300 radar sites around the 48 United States, employing a mix of older AN/CPS-1 early warning and CPS-5 search radars as well as more modern CPS-6B (combined search and height finder functions) and FPS-3 search radars. Due to technical difficulties, siting issues and budget restrictions, the Air Force downgraded the planned SUPREMACY deployment to 61 radars and then halted deployment at 13 sets. The PERMANENT network served as the planned follow-on to SUPREMACY; planning and site surveys commenced in December 1949. The initial plans involved 75 sites equipped with the CPS-5, with emphasis on coverage of the population and industrial centers of the northeast and west, followed by emplacement in the southeastern and central sections of the United States. The Air Force planned 10 centers for command and control purposes with an operational date no later than 1 July 1951. However, while development of the PERMANENT network continued, the Air Force decided to get an interim air defense radar system up and operating with the equipment on hand, deploying AN/CPS-5s under the designation LASHUP (for many analysts, “lashup” served as the perfect description as it brought images of an obsolescent radar lashed with frayed rope to the top of an old pole). Imagery aside, deployment occurred through three phases: Phase I, with initial emergency deployment around high-value locations primarily in the northeast, northwest and in the vicinity of the US’s nuclear development centers; Phase II, the northeastern United States; and Phase III, the Pacific extension south into California. By the end of 1950, 43 LASHUP radar sites were operational. Whatever its limitations, LASHUP at least constituted an initial radar network for the defense of the United States and the timing proved fortunate, as developmental problems pushed the PERMANENT deployment until early 1952. Concurrent with PERMANENT, the Air Force initiated research and development of the follow-on system, designated the MOBILE network. Planned for installation at 44 additional locations including a growing number of Strategic Air Command bases, the MOBILE network incorporated the AN/MPS-7 search, AN/MPS-11 search and AN/MPS-14 height-finder radars. They were in fact mobile radars, developed from fixed radar designs; in advance of the development of the new network, Headquarters US Air Force decreed that all radars would indeed by mobile, mounted on trailers or similar and ready for immediate deployment elsewhere in the world in the event of an emergency. Air defense commanders fought this edict and won out, receiving permission to mount the mobile radars on fixed towers at the desired locations. ARCHIVES & ARCHITECTURE 29 HISTORICAL EVALUATION By June 1951, Air Defense Command teams completed site surveys for 44 (now) SEMI MOBILE program sites (designated M) nationwide. The Air Force subsequently approved a second phase of construction at 35 locations (sites designated SM), followed by a third and final laydown of 29 radars (designated TM). In California, the PERMANENT network started taking form in October 1950, when the 668th AC&WS received orders to establish detachments on top of Marin County’s Mount Tamalpais and at Point Arena, between San Francisco and Crescent City. On 5 May 1950, at the south end of the Golden State, the Air Force activated the following aircraft control and warning squadrons for manning and operation of PERMANENT program long-range radar sites: 669th AC&WS – Fort MacArthur, LASHUP site L-43, moved to Santa Rosa Island (PERMANENT site P-15) in February 1952 670th AC&WS – Camp Cooke, site L-41, moved to San Clemente Island (P-39) in August 1951 750th AC&WS – Edwards AFB, site L-40, moved to Atolia (P-59) in January 1952 751st AC&WS – NCBC Port Hueneme, site L-42, moved to Mount Laguna (P-76) in February 1952 Up north, the PERMANENT program sites started operations towards the end of the year, continuing into the spring of 1951. The first to occupy its site was the 668th AC&WS, which had transferred to the Mather AFB LASHUP facility (L-37) in March 1950; it began operating Mather’s replacement PERMANENT radar site (P-58) in October 1951. Elsewhere, four squadrons stood up on 27 November 1950: 666th AC&WS – Mount Tamalpais (P-38) 774th AC&WS – Hamilton AFB, moved to Madera (P-74) in March 1951 776th AC&WS – Hamilton AFB, moved to Point Arena (P-37) almost immediately 777th AC&WS – Klamath (P-33) The activation of the 775th Aircraft Control & Warning Squadron at Cambria (P-2) on 7 March 1951 concluded the PERMANENT program deployment in California. Air Defense Command subsequently manned and equipped two additional long-range radar sites as inland backups to the coastal. In mid-1956 the 856th AC&WS (activated at Hamilton AFB on 8 September 1955) occupied the state’s only SEMI MOBILE Phase II installation at Red Bluff Air Force Station (site designation SM-157). Roughly a year later, the 682nd AC&WS fully manned California’s only Phase I site at Almaden AFS (M-96). Almaden was the last of Air Defense Command’s long-range radar sites to go “on watch” in California and, as fate would have it, would serve as one of last Air Force-manned and operated radar sites in the Golden State. ARCHIVES & ARCHITECTURE 30 HISTORICAL EVALUATION 682nd Radar Squadron Geiger Field/Kirtland AFB/Hamilton AFB/ Almaden AFS (M-96/Z-96) 1 Dec 53 – 682nd Aircraft Control & Warning Squadron activated at Geiger Field, WA, with the equipment and some of the personnel of the Alabama ANG 115th AC&WS. Upon activation the squadron came under assignment of the 4702nd Defense Wing (Geiger Field), Jan 54 – The 682nd AC&WS transferred to Kirtland AFB, NM for reassignment to the 34th Air Division (Defense) 13 Jul 54 – The 682nd AC&WS was reassigned to the 28th Air Division (Defense) (Hamilton AFB) 1 Aug 54 – The 682nd AC&WS transferred to Hamilton AFB, CA. 24 Jul 57 – Initial operating capability of the 682nd AC&WS at Almaden AFS 31 Sept 57 – The 682nd AC&WS formally transferred to Almaden AFS, CA, station M-96 in the Manual Radar Program (M-96/Z-96) 21 Mar 58 – The 682nd assumed full operational capability at Almaden with AN/FPS-20 search and AN/MPS-14 height finder radars 1 Jul 60 – The 682nd AC&WS was reassigned to the San Francisco Air Defense Sector (Beale AFB, CA) 15 Jan 61 – The 682nd redesignated as a radar squadron (SAGE) 1 Aug 63 – The 682nd RADS(SAGE) was reassigned to the Los Angeles ADS (Norton AFB, CA) 1 Apr 66 – The 682nd was reassigned to the 26th Air Division (Adair AFS, OR) 30 Sept 69 – The 682nd was reassigned to the 27th Air Division (Luke AFB, AZ) 10 Nov 69 – The 682nd was reassigned to the 26th Air Division (Luke AFB, AZ) 1 Feb 74 – The 682nd redesignated as a radar squadron 30 Jun 1980 – The 682nd deactivated at Almaden AFS. ARCHIVES & ARCHITECTURE 31 The Role of Defense Funding in the Making of Silicon Valley D. B. Leeson Abstract—Silicon Valley today is seen as the modern paragon of technology-based economic success, based on venture-backed startups that have brought successive waves of semiconductor, computer, networking and software products to an eager public. But Silicon Valley is not a new phenomenon; its initial development from the early 1900's can be seen as the legacy of defense funding of companies and a university that focused on radio, and then radar technology during two world wars and the Cold War conflicts. I. INTRODUCTION S ilicon Valley is rightly hailed as one of the economic and technologic miracles of our time. The progress from the early days of radio to the latest Internet, mobile and software products can lead one to think that consumers have always been principal customers of Silicon Valley startups and successful companies. But scholarly authors espouse the consensus that Silicon Valley is not a new phenomenon. They trace its roots back over 100 years to the first decade of the Twentieth Century, when the electrification of California was in full swing and radio communications technology, controlled by Marconi patents, was in its infancy. The shipping fleets and navies of the world were among the first to fund radio communications. The San Francisco area was home to major Pacific shipping companies whose needs for affordable and independent radio systems sparked the founding of local radio manufacturers. Radio and vacuum tubes, and then the defense radar of WWII and especially the Cold War, set the stage for the emergence of Stanford University, the venture capital business and the successive waves of semiconductor, computer, network, cell-phone and software companies that employ our local population. A close examination reveals the essential role of defense and other government funding that ultimately made possible the emergence of today's worldfamous companies and local universities. We will see that the most vigorous elements of modern technology economy ultimately trace their existence to defense funding, the aim of which was to strengthen our nation during two world wars and the Cold War conflicts. II. ORIGINS IN RADIO In 1909, funded by faculty and San Francisco investors, Stanford graduate Cyril Elwell founded the company that became the Federal Telegraph Corporation, with a license in the arc transmitter of the Danish inventor Poulsen as a technological edge to win contracts from the US Navy. The US effort in World War I employed radio equipment from Federal, and the company grew to prominence. Oakland's Magnavox and other startups were spin-offs of Federal. When WWI ended, foreign-owned radio companies operating in the US, such as Marconi and Telefunken, were appropriated at the insistence of the Navy into a new corporation, Radio Corporation of America (RCA). As a side effect, this created monopoly patent pools in radio (RCA) and telephony (AT&T). Key among the patents were those for the DeForest vacuum tube, which underlay the next advances in electronics. The next stage of the development of Western technology companies centered on devising new vacuumtube designs that could circumvent patent litigation. Ralph Heintz, a 1919 Stanford graduate, founded a company that became Heintz & Kaufman to manufacture vacuum tubes of a novel design using Tantalum electrodes in a non-infringing geometry. These were used in radio systems to equip the fleet of his sponsor, Dollar Steamship Company of San Francisco. Out of caution for exposure to patent litigation, Dollar discouraged Heintz from other markets. Two of his young employees, William Eitel and Jack McCullough, radio amateurs like Heintz, had adapted the Heintz tube for the amateur use. But with the disinterest of Dollar in that market, in 1934 in the depths of the Great Depression, they left to found their own company, EitelMcCullough (Eimac). Their tubes exhibited durability superior to others, and soon became the de facto standard for high-power amateur radio. This brought Eimac to the attention of Army and Navy engineers (many of whom were also radio amateurs) who were designing the first military radars. Their insistence on Eimac-design tubes elevated the company to the position of one of the principal suppliers of vacuum tubes in World War II. The Depression also impacted Federal Electric, which was acquired by ITT and moved to New Jersey. A key vacuumtube engineer, Stanford graduate Charles Litton, was determined to stay in California. He founded his own company, Litton Engineering Laboratories, to make improved glass lathes and vacuum pumps of his own design for vacuum-tube manufacturing. Litton, also a generous member of the amateur radio community, was personally supportive of Eitel and McCullough as well fostering a vacuum-tube laboratory for another radio amateur, Stanford's Prof. Fred Terman, also a consultant to his former classmate Heintz. III. RADAR AND MICROWAVES During this same period, Sigurd Varian, a Pan American pilot, foresaw the need for a radio means of landing safely through night, cloud and fog, and even for detecting airplanes for defense. His elder brother, Stanford physicist Russell Varian, was aware that very short wavelengths would permit the highly directive antennas required for such a system. But he also recognized that the vacuum tubes of the time were © 2014 D. B. Leeson – may be quoted with attribution 2 limited in their ability to generate sufficient power at short enough wavelengths to do the job. At Stanford, Russell Varian had been a roommate, and later shared an office with, William Hansen. In 1935, spurred by his interest in accelerating electrons, Prof. Hansen, after extensive discussions with Varian, had invented the microwave cavity resonator. Devoted to invention and schooled in patents, Varian advised Hansen to secure what would become a valuable patent. The Varian brothers were determined to create a microwave source that would meet their needs. They returned to their central California home and, with a third brother Eric, set up a laboratory for the project. By 1937 the Varians needed the support of an established physics laboratory and Hansen's expertise, and in May Russell returned to Stanford to share Hansen's office again, bringing Sigurd, an excellent machinist. They became unpaid research assistants with a $100 budget for materials, and by July the three men had conceived the idea for the klystron, which was demonstrated in October. The resulting patent was to be one of the most valuable properties of the University, yielding royalties and recognition. It would also make possible the development of microwave radar, which would prove to be one of the decisive technologies of the coming war. Stanford was then still a regional college, and was also experiencing the financial difficulties of the Depression. It welcomed the offer of multi-year research funding and ongoing royalties from the Sperry Gyroscope Company of New York, a manufacturer with defense experience in aircraft instruments. In 1940, when WWII appeared inevitable, Hansen, the three Varian brothers and Hansen’s protégé students Edward Ginzton and John Woodyard moved to Long Island to continue their radar work at Sperry for the duration. IV. HEWLETT-PACKARD Charles Litton had been generous in his mentoring of Stanford's vacuum tube work, and would make one additional contribution that would have lasting effect. In connection with its funding of Stanford's klystron development, Sperry paid an additional $1,000 for the rights to a patentable idea that Litton had donated to Stanford. In the hands of Prof. Terman, now the head of the Electrical Engineering Department, this money played a key role in the founding of the company that would become a flagship of the area, the Hewlett-Packard Company. David Packard, yet another of the radio amateurs educated at Stanford, graduated in 1934 and, finding work scarce in those Depression days, departed east for an engineering job at General Electric in New York. His good friend William Hewlett also graduated at the same time, but was able to afford to continue his education at M.I.T. and then again at Stanford. Terman had taken Packard and Hewlett to visit local companies, and the three had talked about forming a company. But without funding, and with Packard just married, the GE job was precious in the Depression and the prospects for a return to California did not look bright. But in 1938, with the Sperry money in hand, Terman was able to bring Packard back for a paid research assistantship. Having become a capable vacuum-tube researcher at GE, Packard was put to work on the Litton concept, spending mornings in class, afternoons in the lab under the tutelage of Varian and evenings working with Litton at his company. A patent application was filed naming Varian and Packard as inventors. During this time, at Terman's suggestion, Hewlett was exploring a unique audio oscillator instrument for his Engineer's thesis. Hewlett made a breakthrough in July 1938 and had a working instrument to show by August. Because he had worked without University funding, the resulting patent was in Hewlett's name. This became the foundation on which Hewlett and Packard built their company, which became a legendary success. Although it was not a defense contractor, its instruments were largely bought by companies that were, and by the time of the Korean War, Hewlett-Packard had grown to be a major company. V. RADAR, STANFORD AND VARIAN In late 1940, the government's Radiation Laboratory was established at M.I.T. to develop microwave radar for the coming war. The secret RadLab was staffed with academic cyclotron physicists. Hansen, already recognized as the founder of microwave electronics, was asked to educate them in the practice of microwave radar. A year later, Terman was called to head the secret Radio Research Laboratory at Harvard, tasked with developing countermeasures against enemy radars. Along with the atom-bomb project, these were major government investments in defense science and technology. As WWII came to a close, Terman foresaw that this funding could be continued at Stanford if he assembled suitable research staff. Stanford set up a Microwave Laboratory for the returning Hansen, and an Electronics Laboratory was staffed by returning RRL scientists to continue their work on countermeasures. His strategy for distinction focused on attracting scientific talent in key areas – "Steeples of Excellence" – capable of winning federal funding. Over the next two decades, the majority of funding received by these two labs and their progeny came from the government, and even in recent times Stanford was raising some 90% of its research budget from federal sources. In the same period, the returning Hansen-Varian group founded the company Varian Associates, which quickly found its early business in defense applications of the klystron. The success of Varian Associates and Eimac encouraged the creation of other local companies in the microwave tube business, largely funded by the defense imperatives of the Cold War. At the same time, the work in countermeasures led to the founding nearby to Stanford of a number of successful defense contractors in the applications of that technology. Hansen's development of the linear accelerator, coupled with the realization of high-power klystrons in his laboratory, led directly to the accomplish– ments of the Stanford Linear Accelerator Center (SLAC). VI. VENTURE CAPITAL AND SEMICONDUCTORS This, then, was the environment of the 1960's, when Terman was able to attract the beginnings of the semiconductor industry to the area. The realization that 3 startup companies could be remarkably rewarding investments had been amply demonstrated by the companies that had relied largely on government customers, and the success of Terman's strategy for Stanford had elevated it to the level of an international research university. The transistor, a solid-state replacement for many of the functions of the vacuum tube without many of its drawbacks, was invented at the Bell Telephone Laboratories in 1947. This development flowed directly from WWII work on Silicon radar diodes. In 1964, Terman brought William Shockley to Palo Alto to form a commercial venture in semiconductors. Shockley recruited a cadre of scientists who subsequently left to found Fairchild Semiconductor, and then the gamut of later semiconductor companies that gave rise to the name "Silicon Valley" in 1971. The invention of the planar process and then the integrated circuit created new possibilities for miniaturization that soon found application in ever-smaller and more powerful computers. Initially, only the government could afford the premium cost of these products, and the first years of the semiconductor business were largely a partnership among the device manufacturers, Cold-War funded defense contractors and the government itself. Fairchild, National Semiconductor and Intel were all dependent on this defense spending to launch their later commercial successes. connection with the Linear Accelerator, has come from government sources. The successes of the defense companies that arose from Stanford's developments gave encouragement to the rise of venture capital. The area continues to benefit today from the legacy of the government's role as the initial sponsor of new and high-risk technology. VII. COMPUTERS, N ETWORKS AND SOFTWARE Stuart W. Leslie, The Cold War and American Science: The MilitaryIndustrial-Academic Complex at MIT and Stanford, Columbia University Press, 1993; see also S. W. Leslie and B. Hevly, “Steeple Building at Stanford: Electrical Engineering, Physics, and Microwave Research,” Proc. IEEE, vol. 73, No. 7, July 1985, pg. 1169-80. The subsequent stages of the Silicon Valley story have progressed through the introduction of personal computers, the creation of the Internet (itself initially a defense-funded concept), mobile devices and the software for the use of that infrastructure for news, research and social networking. The rise of businesses such as Apple, Google and Facebook has created vast fortunes, as well as a frenzy of imitators. At the same time, the ability to compress millions of devices into a single integrated circuit has given rise to great successes in cellular telephony, WiFi, Bluetooth and satellites, all wireless technologies that owe their very existence to the radio and radar developments of the previous century. All of these advances can be traced back to defense-funded initiatives of the two world wars, but particularly to the expansion of government technology investments during the Cold War. The contribution of this funding to the emergence of Silicon Valley should be appreciated. REFERENCES Steve Blank, “Hidden in Plain Sight: The Secret History of Silicon Valley,” http://steveblank.com/secret-history/ Robert Buderi, The Invention that Changed the World: How a Small Group of Radar Pioneers Won The Second World War, Simon & Schuster, 1996. C. Stewart Gillmor, Fred Terman at Stanford: Building a Discipline, a University, and Silicon Valley, Stanford University Press, 2004 E. L. Ginzton, " The $100 Idea: How Russell and Sigurd Varian, With the Help of William Hansen and a $100 Appropriation, Invented the Klystron," IEEE Spectrum, Vol. 12, No. 2, February 1975, pg. 30-39; also see Dorothy Varian, “The Klystron Invention,” Ch. 13 in The Inventor and the Pilot: Russell and Sigurd Varian, Pacific Books, 1983. Christophe Lécuyer, Making Silicon Valley: Innovation and the Growth of High Tech, 1930-1970, MIT Press, 2005. Timothy Lenoir, "Myths about Stanford's Interaction with Industry," http://iis-db.stanford.edu/evnts/4097/TLenoir_Myths_about_Stanford.pdf Rebecca S. Lowen, Creating the Cold War University: The Transformation of Stanford, University of California Press, 1997. Jane Morgan, Electronics in the West: The First Fifty Years, National Press Books, 1967 Arthur L. Norberg, "The Origins of the Electronics Industry on the Pacific Coast," Proc. IEEE, Vol. 64, No. 9, September 1976, pg. 1314-1322. Norman Pond, The Tube Guys, Russ Cochran Publisher, 2008. Arun Rao, "Partners: Bill Hewlett, Dave Packard and Fred Terman at HP and Stanford (1930-1970)" in Arun Rao and Piero Scaruffi, A History of Silicon Valley: The Greatest Creation of Wealth in the History of the Planet, Omniware 2011 http://scaruffi.com/svhistory/sv/chap76.html Timothy Sturgeon, "How Silicon Valley Came to Be," in Martin Kenney (ed.), Understanding Silicon Valley: The Anatomy of an Entrepreneurial Region, Stanford University Press, 2000. VIII. CONCLUSION The entrepreneurial spirit of Silicon Valley developed over an extended period, facilitated by the concentration in the San Francisco Bay Area of requirements, visionary technologists, a responsive university and ready capital. The unique attitudes of mutual support and cooperation arose early in the close-knit radio community, and have served the industry well even with the recent rise of the more heated competition. The great expansion of government funding, particularly significant during the period of the Cold War, was key to the emergence of Silicon Valley. Since before WWII the majority of research funding at Stanford, especially in From 1968-1993, David B. Leeson was the founding CEO and Chairman of California Microwave, Inc. Since 1994 he has been a Consulting Professor at Stanford University. State of California – The Resources Agency DEPARTMENT OF PARKS AND RECREATION Primary # HRI # PRIMARY RECORD Trinomial NRHP Status Code Other Listings Review Code Page 1 of 15 P1. Other Identifier: Reviewer Date *Resource Name or #: (Assigned by recorder) Mount Umunhum Radar Tower Almaden Air Force Station (closed)/ Building 102: Radar Tower AN/FPS-24 *P2. Location: Not for Publication Unrestricted *a. County Santa Clara and (P2b and P2c or P2d. Attach a Location Map as necessary.) *b. USGS 7.5’ Quad Los Gatos Date 1980 photorevised T.9S. ; R.1E.; Mount Diablo B.M. c. Address none (former Almaden Air Force Station, Mount Umunhum City Los Gatos Zip 94033 d. UTM: (Give more than one for large and/or linear resources) Zone 10S; 600847 mE/ 4113038mN e. Other Locational Data: (e.g., parcel #, directions to resource, elevation, etc., as appropriate) Assessor’s Parcel Number: 562-08-003 *P3a Description: (Describe resource and its major elements. Include design, materials, condition, alterations, size, setting, and boundaries) Located on the flat peak of Mount Umunhum in the Santa Cruz Mountains, the 5 story concrete radar tower that once operated at Almaden Air Force Station remains a prominent structure at the edge of Santa Clara County. Built within a large complex of buildings and structures that constituted this manned radar surveillance site during the Cold War, the iconic nature of the structure has instills a sense of time and place to valley residents who lived their lives during the emergence of Silicon Valley as a major military and technological innovation center during the latter part of the twentieth century. The mountain top, now devoid of most of the physical remainders of the station following demolition of the complex of buildings in 2013, is today a significant physical reminder of an important period in Santa Clara County history. (Continued on page 2, DPR523L) *P3b. Resource Attributes: (List attributes and codes) HP34. Military Property *P4 Resources Present: Object Building Structure Site District Element of District Other (Isolates, etc.) P5b. Description of Photo: (View, date, accession #) View facing northwest, Sept. 2013 *P6. Date Constructed/Age & Sources: Historic Prehistoric Both 1959-1961/53+ years old. *P7. Owner and Address: Midpeninsula Regional Open Space District 330 Distel Circle Los Altos, CA 94022-1404 *P8. Recorded by: (Name, affiliation, and address) Franklin Maggi & Sarah Winder Archives & Architecture PO Box 1332 San Jose CA 95109-1332 *P9. Date Recorded: May 9, 2014 *P10. Survey Type: (Describe) Intensive *P11. Report Citation: (Cite survey report and other sources, or enter “none”.) Archives & Architecture, LLC, Historical Evaluation, Mount Umunhum Radar Tower, Sierra Azul Open Space Preserve, Santa Clara County, California, 2014. *Attachments: NONE Location Map Sketch Map Continuation Sheet Building, Structure and Object Record Archaeological Record District Record Linear Feature Record Milling State Record Rock Art Record Artifact Record Photograph Record Other (List) DPR 523A * Required information State of California – The Resources Agency DEPARTMENT OF PARKS AND RECREATION CONTINUATION SHEET Page 2 *Recorded by of 15 Primary # HRI # Trinomial *Resource Name or # (Assigned by recorder) Franklin Maggi & Sarah Winder *Date Mount Umunhum Radar Tower 4/15/2014 Continuation Update (Continued from page 1, DPR523a, P3a Description) Building 102 is about 65 feet square and about 19,845 square feet in size. It was designed as a utilitarian structure and consists of poured-in-place concrete walls and floors with an integral vertical structural frame of concrete, visible at the exterior where they break the surface profile into three sections. The parapet at the top provides a base for metal railings. The roof contains the original base for the FPS-24 and sail. View of Mount Umunhum summit prior to removal of structures (Basim Jaber) Upon approach from Mount Umunhum Road, the building as a wide entry at the ground level at the center of the façade containing steel doors within a projecting vestibule. Similar but smaller entries (3) exist at the opposite side of the building, all protected by concrete block enclosures and having varying glazed, vented, and flush surfaces. Additional openings are located above the entry of the main façade, the lower containing an original door, and those above currently open and unprotected. Other wall penetrations exist throughout the structure for fenestration and ventilation. Within the interior are large rooms previous utilized for equipment and other supporting purposes. Large concrete columns evenly spaced within the interiors provided interior support for the rooftop equipment and sail. Space dividers composed of concrete blocks still exist, while those constructed of drywall were removed as a part of asbestos abatement. The exterior walls remain unfinished, painted, pour-in-place concrete. The ceilings are a waffle-like grid of concrete showing the exposed grid of structural system designed to support heavy equipment loading. Within the structure are the remains of mechanical and electrical systems including light fixtures, air handlers, plumbing, and equipment platforms. The building is in fair condition and shows exterior deterioration due to removal of the exterior coating and some unrepaired structural distress. Hazardous materials appear to have been remediated. DPR523L * Required information State of California – The Resources Agency DEPARTMENT OF PARKS AND RECREATION CONTINUATION SHEET Page 3 *Recorded by of 15 Primary # HRI # Trinomial *Resource Name or # (Assigned by recorder) Franklin Maggi & Sarah Winder *Date Mount Umunhum Radar Tower 4/15/2014 Continuation Update Typical third floor interior as shown at Mt Hebo AFS, from Steve Weatherly’s radomes.org. The angled console is the control console, and to the rear is the Transmitter. DPR523L * Required information State of California – The Resources Agency DEPARTMENT OF PARKS AND RECREATION LOCATION MAP Page 4 of 15 Primary # HRI # Trinomial *Resource Name or # (Assigned by recorder) Mount Umunhum Radar Tower *Map Name: USGS/AMBAG/DigitalGlobe/USDA Farm Service Agency (via Google) *Date of Map: 2014 *Scale: n.t.s. Current aerial showing Mount Umunhum summit with Almaden Air Force Station structures removed (excepting Radar Tower) DPR523J * Required information State of California – The Resources Agency DEPARTMENT OF PARKS AND RECREATION Primary # HRI # BUILDING, STRUCTURE, AND OBJECT RECORD Page 5 of 15 *Resource Name or # (Assigned by recorder) *NRHP Status Code n/a Mount Umunhum Radar Tower B1. Historic Name: Building 102, Almaden Air Force Station B2. Common Name: Mount Umunhum Radar Tower B3. Original use: Radar Tower B4. Present Use: vacant *B5. Architectural Style: Utilitarian *B6. Construction History: (Construction date, alterations, and date of alterations) Constructed 1959-1961. Radar sail and radar equipment removed in June 1980. Hazardous materials abatement in 2011. *B7. Moved? No Yes *B8. Related Features: Unknown Date: Original Location: Almaden Air Force Station buildings (no longer extant). B9a Architect: Burns & Roe b. Builder: Indenco Engineers *B10. Significance: Cold War Military Theme Area Sierra Azul Open Space Preserve Period of Significance 1959-1980 Property Type Military Applicable Criteria 1 and 3 (Discuss importance in terms of historical or architectural context as defined by theme, period, and geographic scope. Also address integrity.) Shortly after the end of World War II, it became apparent that tensions between the United States and the Soviet Union could not be contained, and they quickly spilled over into an all-out global conflict. With the outbreak of the Cold War in the late 1940s, and then the Korean War in 1950, the U.S. Army and the U.S. Air Force quickly began reestablishing air defenses to protect the United States against manned bomber attacks from the Soviet Union and other enemies. Some air defense radar sites that were used in World War II were reactivated, and many new sites were established, creating a network of bases and warning systems along the United States borders. California, more specifically the Bay Area, was a part of this network of defense. One of 28 stations built as part of the second segment of the Air Defense Command permanent radar network, Mount Umunhum’s Almaden Air Force Station was a U.S. Air Force early warning radar base that operated from 1958 to 1980. The base was constructed as part of the North American Aerospace Defense Command (NORAD) to keep watch over Northern California’s airspace during the Cold War. (Continued on next page, DPR523L) B11. Additional Resource Attributes: (List attributes and codes) HP11. Engineering Structure *B12. References: From (See related report bibliography) B13. Remarks: Proposed landmark nomination *B14. Evaluator: *Date of Evaluation: Franklin Maggi 5/9/2014 (This space reserved for official comments.) From Page & Turnbull, 2011. DPR 523B * Required information State of California – The Resources Agency DEPARTMENT OF PARKS AND RECREATION CONTINUATION SHEET Page 6 *Recorded by of 15 Primary # HRI # Trinomial *Resource Name or # (Assigned by recorder) Franklin Maggi & Sarah Winder *Date Mount Umunhum Radar Tower 4/15/2014 Continuation Update (Continued from previous page, DPR523b, B10 Significance) As part of the conversion to the Semi-Automatic Ground Environment (SAGE) network, the site subsequently gained an upgraded height-finder radar, an AN/FPS-90, as well as an upgraded Ground-Air Transmit-Receive (GATR) facility, in 1958 and 1962 respectively. The conversion to SAGE resulted in the squadron’s reassignment to the San Francisco Air Defense Sector, which operated from SAGE Direction Center DC-18 at Beale AFB, California, which is located 40 miles north of Sacramento. The AN/FPS-20 radar was replaced by a massive 85.5 ton AN/FPS-24 search radar (manufactured by General Electric) atop Building 102, the five-story concrete tower constructed between 1959 and 1961, visible from the valley floor, known today simply as the Mount Umunhum Radar Tower. The site served as the second production AN/FPS-24 in Air Defense Command, following a similar installation at Point Arena AFS (located 150 miles north of San Francisco near California’s coastline), and was one of seven constructed of masonry and reinforced concrete. It functioned as a frequency diverse (FD) long-range search radar designed to operate in the Very High Frequency (VHF) and was the second of only 12 production models built between 1958 and 1962. In 1961, Almaden AFS joined the SAGE system, feeding computer data to a data center at Beale AFB, California. The SAGE Direction Center at Beale AFB was known as DC-18. After joining SAGE, the squadron was re-designated as the "682nd Radar Squadron (SAGE)." In 1963, the SAGE site information was switched to DC-17 at Norton AFB, located near San Bernardino. That same year on July 31, 1963, the Mount Umunhum site was re-designated as NORAD ID Z-96. In 1968, as the result of defense budget cuts and a reduction in the Department of Defense’s emphasis on protection of the country against Soviet-manned bombers, Air Defense Command (ADC) started deactivating its remaining long-range radar sites in the interior of the country. Directed by the Department of Defense partly in recognition of the increased Soviet intercontinental ballistic missile threat and partly due to their proximity to major target areas, the decision to deactivate selected Defense Commands resulted in the loss of six centers at locations around the country. In their stead, the Air Force developed the Back-Up Interceptor Control system (BUIC), with widely-separated long-range radar sites serving as alternate direction centers in the event of an attack on the continental United States. BUIC I, deployed during the early 1960s, was the manual system; BUIC II was the first of two SAGE-capable systems which went operational in 1966 at 14 locations, including Almaden AFS. As part of the conversion, the long-range radar operations building at the station was enlarged to accommodate additional computers and display equipment as well as a command and control room. The buildings also received additional radio frequency and blast hardening in the form of a two-foot-thick outer shell of reinforced concrete with embedded radio frequency (RF) shields. As a BUIC II site, Almaden backstopped the 26th Air Division Air Defense Control Center (ADCC) at Adair AFS near Corvallis, Oregon. After suspension of BUIC II operations in 1968, the improved BUIC III sites at Mount Laguna AFS (east of San Diego, 751st Air Defense Group), Fallon AFS, Nevada (858th ADG) and Kingsley Field, Klamath Falls, Oregon (827th ADG) assumed backup command and control responsibilities for the West Coast, and Almaden reverted to an air defense detection and surveillance mission. In 1979, Almaden AFS came under Tactical Air Command (TAC) jurisdiction with the inactivation of Aerospace Defense Command and the creation of Air Defense-Tactical Air Command (ADTAC). On June 30, 1980, the 682nd Radar Squadron was rendered inactive at Almaden AFS. Its “retirement” left ADTAC with only four Air Force-manned and operated longrange radar stations guarding the Pacific Coast. From the north, they were the 758th RADS, Makah AFS, Washington; 777th RADS, Klamath AFS, California; 666th RADS, Mill Valley AFS, California; and 775th RADS, Cambria AFS, California. The AN/FPS-24 radar antenna “sail” was removed in June 1980 with the height-finder radars at Almaden AFS removed about the same time. (Continued on next page) DPR 523L * Required information State of California – The Resources Agency DEPARTMENT OF PARKS AND RECREATION CONTINUATION SHEET Page 7 of *Recorded by 15 Primary # HRI # Trinomial *Resource Name or # (Assigned by recorder) Franklin Maggi & Sarah Winder *Date Mount Umunhum Radar Tower 4/15/2014 Continuation Update (Continued from previous page) EVALUATION The Mount Umunhum Radar Tower is individually significant at the local level within the former Almaden Air Force Station under Criterion 1 as a prominent and pertinent example of radar operation at the site and within the Santa Clara County itself. Though not the first or only radar erected at the Almaden Air Force Station, it best represents the overall mission and purpose of the Almaden Air Force Station, and has served as a visual symbol of an important era in county history to the county due to its prominent perch above the valley. The Radar Tower remains the most visual and memorable icon, easily recognizable to the entire population of Santa Clara County. It is of historic significance within the county due to its prominent, distinctive image, its important associations, and the expansive understanding of what it represents to the local population. The Mount Umunhum Radar Tower is individually significant locally under Criterion 3 as a unique concrete structure in Santa Clara County that once supported the highest-powered radar antenna at the now decommissioned Almaden Air Force Station site. The Radar Tower is a distinctive architectural specimen for its unique construction as a military radar tower during the Cold War. The radar tower is a distinguished and locally well-known example of utilitarian military architecture. It is a distinctive local monument of this type, associated directly with an important period in military history. The Mount Umunhum Radar Tower possesses integrity of location and setting. The building has not been moved, although the surrounding buildings are in the process of being demolished at the time of the beginning of this study. Integrity of design, materials, workmanship, feeling, and association had been compromised somewhat because the radar sail and related equipment on the roof has long been removed, and technical machinery to operate the radar no longer exists. Like all decommissioned radar installations in the United States, the radar equipment was removed from the site following decommission, but the building itself retains its original appearance. JRP Historical Consulting Services’ California Historic Military Buildings and Structures Inventory, Volume III: Historic Context: Property Types and Registration Requirements (2000) includes a theme of “Early Warning Systems and Electronic Warfare” and a property type of “Major Radar Arrays.” Registration requirements for this property type state that “If the building is found to have supported an important radar set and the building itself retains integrity to its original appearance, the possibility exists that the building could be found to qualify for the National Register.” Nevertheless, the report suggests that “it is unlikely that a major radar [structure] would be intact, including the radar unit itself.” According to the Page and Turnbull Final Historic Resource Study of Former Almaden Air Force Station, Mt. Umunhum (2010), Building 102 (the extant radar tower) was one of three buildings that were determined to best represent the historic function of the former Almaden Air Force Station. It was also determined to be the most impressive structure on the site. Page & Turnbull found the tower historically significant under National Register in a DPR523 recording dated September 2011, but indicated that it lacked sufficient integrity to be listed. The reasons presented failed to address local context, or the fact that it was unlikely that in any situation the radar sail and equipment for this type of facility would be intact, and that the building itself could adequately convey the reason for significance, as it does in Santa Clara County. The structure remains an important representation of the historic background of the former base, and has sufficient integrity to convey its history. DPR 523L * Required information State of California – The Resources Agency DEPARTMENT OF PARKS AND RECREATION CONTINUATION SHEET Page 8 of *Recorded by 15 Primary # HRI # Trinomial *Resource Name or # (Assigned by recorder) Franklin Maggi & Sarah Winder *Date Mount Umunhum Radar Tower 4/15/2014 Continuation Update View of south and east façades of Mount Umunhum Radar Tower, facing northwest. View of south elevation, facing north. DPR 523L * Required information State of California – The Resources Agency DEPARTMENT OF PARKS AND RECREATION CONTINUATION SHEET Page 9 *Recorded by of 15 Primary # HRI # Trinomial *Resource Name or # (Assigned by recorder) Franklin Maggi & Sarah Winder *Date Mount Umunhum Radar Tower 4/15/2014 Continuation Update View of west elevation from Mount Umunhum Road, facing east. Detailed view of door openings with block wrap-arounds, located on north elevation. DPR 523L * Required information State of California – The Resources Agency DEPARTMENT OF PARKS AND RECREATION CONTINUATION SHEET Page 10 *Recorded by of 15 Primary # HRI # Trinomial *Resource Name or # (Assigned by recorder) Franklin Maggi & Sarah Winder *Date Mount Umunhum Radar Tower 4/15/2014 Continuation Update Detailed view of north elevation, facing east. Upwards view of tower from ground. DPR 523L * Required information State of California – The Resources Agency DEPARTMENT OF PARKS AND RECREATION CONTINUATION SHEET Page 11 *Recorded by of 15 Primary # HRI # Trinomial *Resource Name or # (Assigned by recorder) Franklin Maggi & Sarah Winder *Date Mount Umunhum Radar Tower 4/15/2014 Continuation Update Interior view of boiler equipment – ground floor of radar tower. Interior view of view of electrical panels – ground floor of radar tower. DPR 523L * Required information State of California – The Resources Agency DEPARTMENT OF PARKS AND RECREATION CONTINUATION SHEET Page 12 *Recorded by of 15 Primary # HRI # Trinomial *Resource Name or # (Assigned by recorder) Franklin Maggi & Sarah Winder *Date Mount Umunhum Radar Tower 4/15/2014 Continuation Update Aerial view of Almaden Air Force Station, ca. 1970s. Bird’s eye view of Almaden Air Force Station, 1979. DPR 523L * Required information State of California – The Resources Agency DEPARTMENT OF PARKS AND RECREATION CONTINUATION SHEET Page 13 *Recorded by of 15 Primary # HRI # Trinomial *Resource Name or # (Assigned by recorder) Franklin Maggi & Sarah Winder *Date Mount Umunhum Radar Tower 4/15/2014 Continuation Update View of FPS-24 radar sail, 1975. Photo courtesy of John Beach. Maintenance being performed on FPS-24 radar sail, 1975. Photo courtesy of John Beach. DPR 523L * Required information State of California – The Resources Agency DEPARTMENT OF PARKS AND RECREATION CONTINUATION SHEET Page 14 *Recorded by of 15 Primary # HRI # Trinomial *Resource Name or # (Assigned by recorder) Franklin Maggi & Sarah Winder *Date Mount Umunhum Radar Tower 4/15/2014 Continuation Update View of radar tower and FPS-24 radar in operation, ca. 1970s. DPR 523L * Required information State of California – The Resources Agency DEPARTMENT OF PARKS AND RECREATION CONTINUATION SHEET Page 15 *Recorded by of 15 Primary # HRI # Trinomial *Resource Name or # (Assigned by recorder) Franklin Maggi & Sarah Winder *Date Mount Umunhum Radar Tower 4/15/2014 Continuation Update Front and back cover of brochure for the 682d Radar Squadron operating out of Almaden Air Force Station. Front cover features sketch of the radar tower and FPS-24, back cover features the emblem of the United States Air Force Air Defense Command (1946-1968). DPR 523L * Required information