Download 03/08/2007 - Colorado Secretary of State

FILING - 12/02/2010
Basis and Purpose
Chapter 1 - Fishing
Basis and Purpose:
These regulations amend Chapter 1 – Fishing – of the Wildlife Commission Regulations. These
regulations are designed to manage statewide aquatic resources and provide a diversity of
angling recreation opportunities for resident and nonresident anglers throughout Colorado.
The attached Wildlife Commission regulations are the result of extensive public involvement and
application of biological information on aquatic species. All regulation changes are based on the
best available biological information and are designed to manage aquatic resources towards
stated objectives. In addition to annual changes, these regulations specifically address the
following:
Spearfishing
Northern pike has been added as a species that may be taken by this method statewide. In
addition, spearfishing regulations on Pueblo Reservoir have been modified, specifically allowing
the practice for certain species. These changes increase spearfishing opportunity in response to
requests from spearfishing anglers in Colorado.
Collection and Use of Baitfish
These regulations largely restrict collection and use of baitfish to use in the same body of water
from which the fish were collected, with the exception of the lower Arkansas River Valley, which
continues to allow collection and transportation of baitfish within certain counties due to the
interconnectivity of the water in that basin. These regulations intend to minimize the potential
hazards associated with collection and movement of fish from one body of water to another,
namely proliferation of aquatic diseases and/or aquatic nuisance species, and unintended
species translocation. Collection and use of baitfish remains prohibited above 7,000 feet east of
the Continental Divide, and in all waters west of the Continental Divide except Navajo Reservoir.
Alberta Park Reservoir
 Remove special cutthroat trout regulations
The existing special regulation (#108-6) “Fishing is by artificial flies and lures only, all cutthroat
trout must be returned to the water immediately upon catch,” was discussed and implemented in
1995 with the goal of creating a trophy Rio Grande cutthroat trout (RGN) water. Between 1996
and 2009 approximately 77,000 RGN fingerlings have been stocked into this resource averaging
over 5,000 fish per year. Despite restrictive harvest regulation and annual stocking, Rio Grande
cutthroat trout abundance continues to decline. Gillnet catch (CPUE) has been on the decline
every year since the regulation was implemented (1998 (1.3); 2003 (0.3); 2004 (0.2); 2009
(0.03)). However brook trout abundance has been on the rise and 42% of the population
sampled in 2009 was over 12 inches in length with individual fish approaching 15 inches. Despite
our best efforts we have been unable to create a trophy Rio Grande cutthroat trout water in the
presence of brook trout. However we are confident that a quality brook trout population is
attainable through restrictive harvest regulation.
Arkansas River (below Pueblo Reservoir)
 Add regulations to a section below Pueblo Reservoir requiring artificial flies and lures
only, and catch and release for all trout 16 inches or greater
The fishery of this stretch of the Arkansas River has greatly improved over the past 20 years.
During that period the City of Pueblo has developed paved access trails and increased points of
river access, making it much more accessible to urban anglers. In cooperation with the Corps of
1
Engineers, the Arkansas River Legacy Project was completed in early 2004. This project
provided for in-stream habitat structures designed to increase fish holding water and improve the
quality of fishing. Also during this period catchable trout stocking was greatly increased on the
river below the dam while the DOW was adjusting to new trout production under the whirling
disease policy. As a result, the fishery improved and received much attention, both locally and
along the southern Front Range. This river reach became particularly popular as a winter fishery
for fly fishing enthusiasts seeking open water and relatively mild conditions, as well as for a
diverse angler group in Pueblo looking for fishing opportunities close to home for trout, walleye,
and bass. The current fishing regulations on this stretch of the Arkansas River are the standard
statewide limits (four trout), with no terminal tackle restrictions (bait allowed). Restricted harvest
regulations have been used in many Colorado rivers to improve the quality of wild trout
populations. Those regulations have been generally effective where the underlying problem has
been overharvest – when the number of fish being taken exceeds the ability of the fish population
to naturally sustain itself. As demonstrated from population monitoring there is virtually no natural
trout reproduction in the river, and harvest in this urban fishery is supported by the stocking of
catchable trout. In addition, the quality of this fishery is limited by high/ low flows and habitat
limitations. These factors result in a biologically complex fishery, and one that must be managed
for a diversity of fishing interests. Nonetheless, fishery objectives for the reach of the Arkansas
River include balancing angler harvest of stocked catchable trout with opportunities for quality
trout angling.
Arkansas River Valley Reservoirs (Nee Gronda, Nee Noshe, John Martin, Adobe Creek)
 Allow 10-fish possession limit and remove one fish over 21 inches restriction on walleye
In 2006, the walleye/saugeye regulation at a number of SE reservoirs was changed with the
intent of improving the quality of the fishery by restricting harvest to fish larger than 15” with a
five-fish bag/possession limit of which only one fish could be over 21 inches. This regulation
change came prior to a time when water supplies and management resulted in reduced lake
levels, significant fluctuation, and/or poor water quality; which has limited the potential for quality
walleye/saugeye populations (regardless of harvest). A complete winter kill occurred at Nee
Gronda Reservoir this year with total loss of that fishery. Nee Noshe and John Martin reservoirs
continued to suffer from very low storage, and Adobe Creek Reservoir is just showing signs of
recovery from drastically low levels a couple of years ago. While there is generally good angler
support for quality fishing opportunities for walleye and saugeye in the lower Arkansas basin
reservoirs – water issues are limiting those populations and fishery management goals for
acceptable size structure. Managing for large/trophy walleye and saugeye is being frustrated by
the lack of suitable conditions (habitat quality, habitat availability, forage, etc) due to low water
conditions. Harvest opportunities are being lost when fish lose habitat, with no commensurate
increase in quality-sized fish. Anglers have been particularly dissatisfied with limitations on
possession; as multi-day trips to those reservoirs are common, but they are limited to a one-day
bag limit. In addition, there has been strong local support to eliminate the restriction on harvest of
fish over 21”. A fishing regulation is proposed that would provide opportunity for harvest of
acceptable sized fish while allowing potential for development of quality-sized walleye/saugeye at
Nee Gronda, Nee Noshe, Adobe Creek and John Martin Reservoirs. The key would be to
regulate and manage walleye/saugeye populations in synch with the existing fisheries and habitat
to achieve an acceptable balance of quality fishing and harvest.
Big Thompson Ponds
 Add a one-fish limit for bass
On one end of the spectrum, catch and release bass fishing in Colorado has produced quality
angling for the target species while simultaneously producing more desirable sunfish population.
On the other end, the 15-inch bass minimum (bag/possession of five) currently present on many
of Colorado’s smaller waters has generally proven ineffective in producing good angling
opportunities for bass and sunfish. To strike a balance between these extremes, we propose a
regulation that would improve bass quality while still allowing anglers to harvest a trophy sized
2
fish. Heavy usage on some of Area 2’s smaller waters such as the Big Thompson Ponds cannot
sufficiently support the current bag and possession limit of 5 fish. For example, a 2009 creel
survey on McCall’s Lake near Longmont (30 acres) found that 7,914 anglers spent a total 18,486
hours fishing over a 6 month period (May-October). Similar pressure is likely present at Big
Thompson Ponds. Liberal bass harvest on the ponds has resulted in poor bass recruitment and
stunted populations of bluegill, green sunfish, and yellow perch. In order to achieve and maintain
a balanced fish population, proper stocking and fish harvest are essential. Largemouth bass are
stocked annually; however, current angling pressure and harvest is not matched by the carrying
capacity of the ponds. Brood-stock bass are virtually absent while populations of sunfish are
extremely abundant. In this case, reducing bag and possession limits will (1) promote increased
natural reproduction, (2) spread bass harvest over a larger number of anglers, and (3) bring the
ponds in better balance by increasing predation on stunted sunfish populations.
Blue Mesa Reservoir - Lake Trout
 Make bag/possession limit for lake trout unlimited, with only one fish per day over 38
inches
Concerns regarding lake trout predation on stocked kokanee and rainbow trout resulted in
liberalization of lake trout bag and possession limits at Blue Mesa Reservoir in 1996 to an eightfish bag and possession limit. Since that time, the lake trout population has continued to expand.
Increased lake trout predation upon kokanee and rainbow trout has resulted in reduced survival
of these species and has significantly reduced angler opportunity and use at Blue Mesa
Reservoir. To attempt to restore balance at Blue Mesa reservoir, CDOW staff has recommended
harvest of small to medium-sized lake trout. In the fall of 2009, CDOW staff began work to
reduce the lake trout population size by mechanical removal of lake trout less than 30 inches in
length. Lake trout population monitoring was completed in the spring of 2010. This sampling
indicated that the lake trout population has expanded considerably in recent years. Lake trout
under 20 inches in length were 6.7 times more abundant than was documented in 2000 through
2002. Larger lake trout over 30 inches in length were also present in larger numbers as angler
harvest of these larger fish has not kept up with population growth. 2010 capture of lake trout
over 30 inches in length was 1.7 times greater than the average number caught in 2000-2002.
Interest in fishing for trophy lake trout at Blue Mesa Reservoir has increased considerably since
the late 1990s and has resulted in several lake trout state records coming from the reservoir in
recent years. Reduced numbers of kokanee prey have endangered the ability to support a trophy
lake trout fishery. This reduction in kokanee prey is the result of increased predation pressure by
the expanding lake trout population. Individual lake trout grow incredibly fast at Blue Mesa
Reservoir and show the highest rate documented at any North American water. This has resulted
in lake trout which are able to reach 40 inches in length within 15 years. This incredible growth
can quickly lead to increased stockpiling of lake trout and increased predation if more restrictive
harvest size limits are implemented. In an effort to restore balance in the Blue Mesa Fishery, a
regulation is recommended that allows increased lake trout angler harvest while maintaining
trophy lake trout opportunities. Angler harvest of larger lake trout has generally been low, as
many anglers release larger fish that are caught. This has allowed larger lake trout to increase in
numbers, in spite of the lack of protective regulations on these fish. Numbers of lake trout in the
30-35 inch group have increased significantly in recent years. Limiting harvest of these fish could
increase predation pressure on kokanee and rainbow trout.
Blue Mesa Reservoir - Coal Creek Inlet
 Remove fishing prohibition at the Coal Creek inlet to Blue Mesa Reservoir
Coal Creek is a tributary to Blue Mesa Reservoir which once had a population of rainbow trout
that migrated upstream in the spring to spawn. Recent sampling was completed in 2009 to
assess whether this stream is currently utilized by rainbow trout for spawning purposes. No
rainbows were sampled and it is believed that the stream is no longer utilized by rainbow trout for
natural reproduction.
3
Boulder Reservoir
 Remove special walleye regulations
Boulder Reservoir serves as part of the Colorado-Big Thompson Water diversion system
providing water for agricultural and municipal use. It is also a popular recreation site for anglers.
Boulder Reservoir is stocked with walleye, channel catfish, and black crappie by the Division of
Wildlife. Because of its particular location and the reservoir’s west slope water source, Boulder
Reservoir is relatively unproductive compared with reservoirs which fill via native South Platte
east slope water (Cherry Creek, Jackson Reservoir, Barr Lake etc.). As a result, walleye in
Boulder Reservoir grow slower while annual reproduction by gizzard shad, the forage base
species, is sporadic. Walleye in Boulder Reservoir typically reach the 15 inch minimum midSeptember (stocked 2.5 years prior) whereas walleye in more productive Colorado waters
walleye reach 15 inches during June of the same year. The average condition factor for all
walleye >200mm (8-inches) sampled during 2008 and 2009 was 86 indicating walleye are in poor
condition, a likely result of a limited forage base. The presence of a naturally reproducing
population of smallmouth bass further compounds matters as these fish partially compete with
walleye. Angler interviews with the local DWM found that most anglers contacted catch bass or
walleye smaller than 15 inches and many if not most don’t keep fish; we assume this is in part
that it is difficult to hook a legal sized walleye. Currently anglers are restricted to harvesting
walleye that exceed 15 inches, with only 1 walleye in the limit exceeding 21-inches. This
regulation has little biological support as (1) walleye growth rates are slower relative to other
Colorado walleye waters, (2) virtually no walleye actually exceed 21-inches, (3) the reservoir does
not serve as a brood water for an egg take operation, and (4) no natural reproduction occurs
within this reservoir. To improve angler harvest and subsequent walleye growth rates (reduced
competition) we recommend removing the special regulation on Boulder Reservoir. This
reservoir should be managed under statewide regulations that stipulate anglers can harvest up to
5 walleye of any size. Under this management strategy, the walleye population in Boulder
Reservoir will likely mimic populations in Union Reservoir and Lake Loveland which fall under the
statewide regulation and function quite well giving the angler the choice at which to harvest a
walleye.
Carter Lake
 Remove walleye slot size limit; set maximum walleye size limit at 21 inches; increase
possession limit to six fish with a three-fish bag limit
Carter Lake is a deep, unproductive reservoir located west of Loveland on Colorado’s northern
Front Range. Rainbow trout, splake, kokanee, walleye, yellow perch, and largemouth bass
provide fishing opportunities for both cold and warmwater species in the same reservoir.
Walleye, bass, and perch naturally reproduce in Carter while trout, splake, and kokanne are
stocked by the Division of Wildlife. Prior to a regulation change in 2003, Carter’s walleye
provided a top-level predatory component to the food web that enhanced fishing for kokanee,
trout, splake, lake trout, and contributed to better growth of yellow perch and largemouth bass via
a competitive reduction attributable to walleye predation. During the mid-90’s walleye in Carter
were relatively sparse and smaller; following a regulation change in 2003 which reduced angler
harvest, the population rebounded and expanded to a point the reservoir cannot sustain. For
example, annual fall gillnet surveys completed 1990-2002 yielded an average annual catch rate
0.26 walleye per net hour; between 2003-2009 the average annual catch rate tripled to 0.76
walleye per hour net hour. In addition to population expansion, the size structure of Carter’s
walleye has shifted to a point where much of the population now exceeds 20 inches in length. In
short, more walleye are now present in Carter following the 2003 regulation change and the fish
are much larger. Average annual walleye condition prior to 2003 averaged 119, since the
regulation change average annual condition of walleye measures 100 and has decreased each
year since 2003. The dietary requirement of Carter’s walleye cannot be sustained through
natural forage production; angler harvest should be increased to return the walleye population to
some degree of balance with the forage base. This regulation is intended to increase walleye
harvest to help bring the population into balance.
4
Chatfield Reservoir
 Implement a bag limit of three walleye
The current special walleye regulation at Chatfield Reservoir is in place to protect the brood fish
that supply eggs to the hatchery system for distribution of walleyes throughout the Front Range.
Chatfield Reservoir is stocked annually with walleye fry, which supported a good population prior
to 2007. However, large inflows into the reservoir from the South Platte River during Spring 2007
required the Army Corps of Engineers to release higher than normal amounts of water through
the reservoir outlet into the river below. This resulted in large numbers of walleye being flushed
through the dam into the spillway, where the special regulations do not apply and many were
harvested by anglers. This loss of walleyes from the reservoir population was confirmed by
reduced catch rates during annual population surveys and subsequent spring spawning
operations from 2008-10. Therefore the annual egg production from Chatfield Reservoir was
much lower during those years. A more restrictive regulation is needed to protect the walleye
stocked in 2008 and subsequent years that will replace the mature fish (and possibly fry) flushed
through the dam in 2007. It is anticipated that the ongoing annual stocking of walleye fry will
bring back the population to levels seen prior to 2007, and the new, more restrictive special
regulation could be relaxed, but it will take several years. In the mean time, a new regulation
would protect the smaller number of mature walleye that are still providing eggs to the hatchery
system. In addition, the current special regulation does not apply to the South Platte River below
the dam, where the statewide general regulation is in effect. This creates law enforcement
problems within Chatfield State Park. An officer that may contact an angler with walleye in
possession does not know for sure whether the walleye were caught from the reservoir or the
river, two waters currently under two different regulations.
Cheesman Reservoir
 Modify fishing season regulation and snagging season regulation
Denver Water owns and operates Cheesman Reservoir as a metropolitan water source. January
1 – April 30 Denver Water’s staff closes a gate on a security fence which prohibits angler access
to Cheesman Reservoir. Due to statewide kokanee egg take shortages, Cheesman Reservoir is
being developed as a kokanee brood water. Last year during the first spawn take at Cheesman
Reservoir, DOW staff secured 493,000 kokanee eggs to fulfill the 2010 kokanee stocking
schedule for Cheesman Reservoir and to distribute kokanee eggs to other front range reservoirs.
Cheesman Reservoir could potentially produce 1-2 million kokanee eggs annually. During the
2009 spawn take operation, DOW staff set up a temporary fishing closure in the Goose Creek
arm of Cheesman Reservoir to allow crews to trap net and electrofish mature kokanee.
Numerous times DOW staff entered the reservoir to find closure signs missing, closure fences cut
and vandalized, trap nets that were tampered with and tangled with snagging hooks, and people
snagging behind the closure. Not only did these incidents cost DOW staff time and money to
maintain equipment, signs, and the temporary closure; the snagging hooks became a safety
issue trying to clean out trap nets. Angling use at Cheesman Reservoir is highest May, June,
July, and August. Most anglers during this period of time target trout and smallmouth bass. The
principal use of Cheesman Reservoir October through December is kokanee snagging. Closing
the Denver Water security gate prior to January 1 each year is intended to allow for a safer and
more efficient kokanee egg take operation and increase enforceability compared to the temporary
kokanee closure.
Cheesman Reservoir
 Remove northern pike restriction
Denver Water owns and operates Cheesman Reservoir as a metropolitan water source. CDOW
staff believes this regulation was put into place to create a trophy northern pike fishery at
Cheesman Reservoir. Fishery management at Cheesman Reservoir has changed and
Cheesman Reservoir is now being managed as a kokanee brood water. Protecting larger
5
northern pike at Cheesman Reservoir will only slow down the development of this brood source.
The current northern pike fishing regulation is confusing to anglers. Some anglers believe you
can only harvest one northern pike per day at Cheesman Reservoir but it must be at least 34
inches long. Others believe you can harvest an unlimited number of northern pike per day but
that only one may be 34 inches long.
Cherry Creek Reservoir
 Implement a bag limit of three walleye
The current special walleye regulation at Cherry Creek Reservoir is in place to protect the brood
fish that supply eggs to the hatchery system for distribution of walleyes throughout the Front
Range. The annual stocking rate for walleye fry at Cherry Creek Reservoir was increased to 4
million per year starting in 2007 compared to 2.5 annually in previous years. This produced a
larger number of walleyes in the 19” size class during the 2010 spring walleye spawning
operation, with this size of fish producing most of the eggs during the Cherry Creek spawning
operation. This trend of greater numbers of walleyes in the 19” range will continue due to the
increased stocking rate, but the current regulation would not protect this size of fish. It is
unknown at this time whether the increased numbers of 19” fish will equate to higher numbers of
fish greater than 21” beginning in 2011. Therefore, it is important to protect walleyes in the 1921” size range for several years until it can be determined if the numbers of fish greater than 21”
increases in future years.
Chinns and Sherwin Lakes
 Remove splake restrictions
Both lakes are no longer stocked with splake, and recent surveys in 2007 did not collect any
splake in either lake. These lakes are currently stocked with greenback cutthroat trout, the native
salmonid species for Clear Creek County and the Front Range of Colorado. All other high lakes
in Clear Creek County that are managed for greenback cutthroat trout are under general
statewide bag and possession limits.
Crawford Reservoir
 Remove northern pike restriction
Crawford reservoir is a popular warmwater fishery that supports angling for yellow perch, black
crappie, northern pike, channel catfish, rainbow trout and largemouth bass. Northern pike were
illegally introduced in the early 1990’s and have had a dramatic effect on the fish community of
the reservoir. There is no biological justification for a restrictive harvest regulation on pike; fish
population sampling and creel data indicate that angler harvest has very little influence on the
number or size of pike in Crawford. The current regulation is confusing to some anglers and the
harvest of small pike, which is allowed, is reduced by misinterpretation of the regulation. The
number of pike in the reservoir has been increasing and the quality of other sportfish populations
like crappie, perch, trout and bass is being impacted by excessive pike predation. To establish
more balanced predator-prey dynamics in Crawford, pike numbers should be reduced and angler
harvest should be encouraged. The current regulation also sends a poor message to anglers by
protecting an illegal introduction with a restrictive regulation. Illicit fish movement is a large
problem in Colorado and has impacted many popular sport fisheries as well as native warmwater
fish of the west slope. Illicit fish introductions and other aquatic nuisance species can have
devastating impacts to aquatic ecosystems and preventing illegal introductions is an important
part of preserving the state’s aquatic resources. The Crawford Reservoir pike regulation is one of
the few instances in Colorado where an illegal introduction has a protective regulation. Efforts to
educate anglers on the negative impacts of illicit stocking are undermined when illegal stocking is
rewarded with special regulations.
Duke and Connected Lakes
 Increase minimum size limit for largemouth bass from 15 inches to 18 inches
6
Duke Lake (approximately 6 surface acres) and Connected Lakes-upper and lower (combined
are approximately 50 surface acres) were originally gravel pits that were reclaimed by the CDOW
in 1992. These three lakes are “urban” reservoirs within the city limits of Grand Junction (Mesa
County) in northwestern Colorado. All three waters are part of the City of Grand Junction’s
Riverfront Project and are managed by Colorado State Parks for visitor and recreational uses.
The CDOW manages the fisheries in Duke and Connected lakes as well the adjacent fishery of the
Colorado River. The CDOW currently manages Duke and Connected lakes as warmwater,
nonnative fisheries. Both waters provide anglers the opportunity to fish for bluegill and largemouth
bass. The existing fisheries have self-sustained themselves since the CDOW last stocked these
waters with bluegill and largemouth bass in 1993. In 1996, the CDOW pursued the construction of a
berm around Duke and Connected lakes to protect these waters from inundation during a 50-year
flood event in the Colorado River. The Colorado River connected with Duke Lake in 1995 during a
15-year flood event. The three lakes are adjacent to the mainstem Colorado River which, along with
the 100-year flood plain, has been designated by the U.S. Fish and Wildlife Service as critical habitat
for four endangered fish species (humpback chub, bonytail, razorback sucker, and Colorado
pikeminnow). The CDOW manages this stretch of the Colorado River for native fishes including the
endangered fishes mentioned previously, and those non-listed native species such as the bluehead
sucker, flannelmouth sucker, roundtail chub, and speckled dace. The State of Colorado considers
the roundtail chub to be a Species of Special Concern. The project would have made the nonnative,
warm water fisheries in all three waters compliant with the Nonnative Fish Stocking Procedures of
1996. These Procedures, approved by the Colorado Wildlife Commission and CDOW Director,
specifically mention the need for the berming project in order to manage the warmwater fisheries.
The CDOW determined a seven to eight feet tall berm would be required in some areas around
Duke and Connected lakes. This size of berm was undesirable from a recreation standpoint and the
project did not move forward. The CDOW does not have the approval to supplement the existing
warmwater fisheries in Duke and Connected Lakes because of the pond's position in the floodplain
and connection with the Colorado River is possible. Both lakes support bluegill and largemouth bass
fisheries, and the CDOW is currently managing these fisheries with a limited harvest of 2 largemouth
bass over 15” allowed. This regulation was established in 1996 when the CDOW was actively
pursuing the construction of a berm around Duke and Connected lakes. Local anglers have recently
expressed concern to the CDOW as to why these largemouth bass fisheries are not managed as
catch and release only to ensure a quality bass fishery. These regulations are intended to
compromise by continuing to allow harvest, but also increasing the quality bass opportunity.
East River
 Allow lures to be used in the special regulations section
These regulations bring the East River artificial flies restriction into convention with other artificial
flies and lures restrictions throughout the state and increases the enforciblity of the regulation, as
no clear regulatory distinction is currently drawn between artificial flies and artificial lures.
Fraser River
 Implement artificial flies and lures only regulation and catch and release regulation for
rainbow trout from the headwaters to St. Louis Creek
The towns of Fraser and Winter Park, along with multiple other entities, completed a habitat
improvement project on approximately 2 miles of the Fraser River in 2005. The goal of the project
was to provide better habitat for large, adult trout during periods of artificially low flows caused by
upstream diversions. After completion of the project, the Division of Wildlife stocked multiple sizes
of rainbow trout over a three year period to revitalize the fishery there. This section of river is
mostly open to public access, and is mainly used by fly and lure anglers who support protective
regulations. It is a relatively small stream surrounded by a significant population center. Currently,
standard regulations apply from the headwaters to the confluence with Ranch Creek. From
Ranch Creek downstream to the Colorado River, the bag and possession limit for trout is two fish.
The current regulation is counterintuitive considering the fact that the upper section of the river, in
7
the towns of Fraser and Winter Park, has much more public access, is more visible and more
heavily used. Annual electrofishing surveys have been conducted in several locations on the
Fraser River. The trout population biomass in the reach immediately downstream from the
Vasquez Creek confluence in the town of Winter Park has consisted of 69% brook trout since
2006. In a reach farther downstream, immediately behind the Safeway store in the town of
Fraser, the trout population biomass has consisted of a more balanced mix of brown, rainbow,
and brook trout. Due to stocking of brood cull rainbow trout in the river, densities of rainbow trout
14” or larger peaked in 2008 at 53/acre. In 2009, that estimate dropped to 10/acre. Densities of
brown trout 14” or larger have slowly increased to a high of 20/acre in 2009. There is also a high
density of sculpin in this reach of river, indicating that it does have the potential to maintain high
densities of quality-sized trout. A lack of natural reproduction in brown and rainbow trout has
been observed in the upstream reaches of the Fraser River. Numbers of small (<6”) trout
captured in this area are far below what is normally observed in self-sustaining trout populations.
The combined estimate for brown and rainbow trout less than 6” in 2009 was 76 fish/mile. In a
similar station on the Fraser River several miles downstream, that estimate was 1,698 fish/mile.
Reasons for this are not immediately apparent, but it does present a concern regarding the river’s
ability to sustain significant levels of harvest pressure, in particular for rainbow trout. CDOW staff
met with members of the public at an Anglers’ Roundtable meeting in Granby on April 26, 2010.
The preference expressed by constituents at this meeting was for a catch-and-release regulation
for all trout. However, we believe that robust populations of brook trout in certain reaches can
sustain harvest. In addition, numbers of quality-sized brown trout have steadily increased since
2006, indicating they are able to maintain their numbers under current angling pressure and
harvest rates.
Golden Park Ponds #1 and #2
 Implement artificial flies and lures only regulation
Although not a binding Division of Wildlife regulation, Longmont ordinance currently limits angling
in ponds #1 and #2 to fishing by artificial flies and lures only. Socially the ordnance has received
favorable support however compliance has not been 100% effective caused by differing
jurisdictional boundaries. Biologically, this regulation fits the current fishery management
strategies for each of the ponds on this property.
Green Mountain Reservoir
 Increase the bag and possession limit for lake trout to eight fish
In the fall of 2007, Division of Wildlife Area 9 personnel began receiving reports of spawning
kokanee salmon in Green Mountain Reservoir and the Blue River with infections of gill lice.
Beginning that fall and for each year following, the spawning run of kokanee has become
unreliable and sporadic. Angling for kokanee in both the summer and the winter ice fishing
season has also been unreliable and mostly poor. Gill lice have now been observed in both
kokanee salmon and rainbow trout throughout the Blue River between Green Mountain and Dillon
reservoirs. Coincident with the apparent decline of the kokanee salmon stock in Green Mountain
Reservoir, the quality of lake trout fishing has also declined. Large numbers of small (12-16”) lake
trout exhibiting very poor body condition are commonly observed in anglers’ catches. Gillnet
sampling results from May of 2010 in Green Mountain Reservoir illustrate this issue. A total of 22
lake trout were captured in 64 hours of netting effort, yielding a catch of 0.34 lake trout per hour.
The most common size of lake trout captured was 14 inches. For fish less than 20 inches long,
the average relative weight was 69.4. This is a strong indicator of poor body condition and a
probable lack of adequate forage for fish in this size range. The predator-prey relationship
appears to be out of balance in Green Mountain Reservoir. Based on the high numbers and poor
quality of lake trout caught, there currently appears to be an overabundance of lake trout in the
lake. This population should easily sustain increased harvest rates, and may exhibit increased
quality as a result of the thinning effect that increased harvest may produce. Liberalization of lake
trout harvest would be beneficial to the fishery by moving this relationship toward a more healthy
balance.
8
Henry Lake, Two Buttes Reservoir and Thurston Reservoir
 Allow trotlines and jug fishing
Currently, CDOW allows trot-line and jug fishing at all major Area 12 reservoirs (Adobe Creek,
Horse Creek, John Martin, Meredith, Nee Gronde, Nee Noshe, Nee So Pah, and Queens
reservoirs), except three (Thurston, Two Buttes, and Henry reservoirs) which were omitted during
past regulation review processes. These reservoirs are all warm water fisheries that experience
relatively low fishing pressure, due to the remoteness of their locations and limited accessibility to
the angling public. Trot-lines and jug fishing have not had a detrimental effect to the fisheries of
any of the lakes where they are currently permitted. Participation and harvest tends to be fairly
insignificant compared to over-all angling pressure. Although any species can be caught with
these methods, they tend to be more selective for catfish and wiper. These species have fairly
liberal bag limits and should not put anglers in jeopardy of violation by using these methods.
There is interest in permitting trot-line and jug fishing in the Lake Henry, Thurston Reservoir, and
Two Buttes Reservoir to provide additional opportunity, and to provide consistency with the
trotline and jug fishing regulations in all other Area 12 waters.
Highline and Mack Mesa Reservoirs
 Implement two-fish limit and 15-inch minimum for largemouth bass
Bass regulations have been made consistent on Highline and Mack Mesa, which are immediately
adjacent to one another.
Horsetooth Reservoir
 Remove special walleye regulations
Horsetooth Reservoir is a part of the Colorado-Big Thompson Water diversion system providing
water for agricultural and municipal use. The water diverted from the west slope, upper Colorado
River Drainage, is relatively cool and unproductive compared with other front range reservoirs
that are fed from the lower South Platte River Basin. Horsetooth is a large draw for anglers and
holds high numbers of smallmouth bass and walleye. Walleye are not stocked as this reservoir is
one of the few in Colorado with a naturally reproducing population. As a result of these factors,
this situation requires unique management strategies to maximize the potential of this reservoir.
In 1984, rainbow smelt were introduced to Horsetooth Reservoir in an attempt to provide a forage
base for a walleye population that had declined in numbers throughout the 1970’s. Perch had
been the primary forage base but had failed to keep up with the predator population. Smelt
establishment was highly successful and boosted the walleye population creating high numbers
of large fish that grew very quickly. Unfortunately the smelt were highly efficient grazers of
zooplankton, the foundation of the reservoir’s food chain. They proved to be an unsustainable,
unbalanced forage that crashed the entire reservoir ecosystem in the mid 1990’s by quite literally
eating themselves out of house and home, and were subsequently reduced to undetectable
levels in the reservoir. Walleye growth rates during the apex of smelt in the reservoir supported
the regulation that was put in place. With an abundance of forage, walleye grew past 18 inches in
three or four years and had the potential to reach trophy sizes, requiring a limit on the take of
large fish. The forage base for Horsetooth has not recovered since the crash of smelt.
Complicating things, the reservoir was drawn down to dead pool from 2001 through 2003. This
allowed a return of zooplankton, an opportunity to successfully establish spottail shiners, emerald
shiners and gizzard shad and a reduction of walleye reproduction. However, when the reservoir
was refilled, walleye reproduction skyrocketed past forage production creating a large number of
young fish that immediately set back the forage introductions. Additionally, water quality changes
in the reservoir began to lead to reduced habitat potential for some of the introduced forage
species. This failure of the forage base led to the current situation in the reservoir where there are
a high number of small walleye that grow very slowly. In an age and growth study done in 2008,
all fish under 14 years old still failed to surpass the current minimum size limit. Attempts to
9
establish a forage base since 2004 have been unsuccessful. There are a very high number of
predators in the system and while some years are better than others, the overall trend in walleye
condition has been negative. The most current sampling shows that the walleye population does
not approach the current limits, significantly impacting fishermen’s ability to harvest fish or enjoy
quality fishing. In a creel study done in 2009, 212 anglers were interviewed about walleye fishing.
Those anglers fished for a collective 492 hours and only 14 fish above 18 inches were caught
with only 6 of these actually harvested. In the associated questionnaire, 62% of anglers did not
keep walleye with 46% of them stating that the walleye were not big enough. 52% of all the
Horsetooth anglers were not satisfied with walleye they caught with 50% stating “too small” as the
reason. The solution to this stunting problem is population reduction. This will provide an
opportunity for the forage fish to establish a more sustainable base. As the population is reduced,
the forage fish should rebound and growth rates for the fish that remain will increase significantly.
If the walleye population is not affected significantly, the forage will not increase and we will keep
the same stunted situation that currently exists. We do not have the option to reduce stocking, as
in other reservoirs where fish populations are manipulated by the number of fish planted. The
best way to accomplish this is to allow the anglers to take more fish. Therefore our
recommendation is to remove the special regulation currently in place on Horsetooth Reservoir.
An intermediate regulation may not have a significant enough impact to reduce the population to
a size that allows a forage base recovery.
Jackson Lake
 Clarify where fishing is allowed below the dam and reduce fishing closure in the portion
pertaining to Jackson Lake State Park
Current regulations read as though fishing below the dam in the outlet canal and around the
rotary screen is prohibited. This can be confusing for many anglers as fishing is permitted in the
outlet canal below the dam. Fishing is prohibited in and around the fenced and signed area of
the rotary screen within the canal in order to protect the fish in that portion of the canal. This
regulation should to be re-worded in order to reduce angler confusion. Additionally, regulations
currently close fishing in those parts of the reservoir within the state park after November 1 and
November 30. There is no biological reason for this closure. Fishing could be permitted on the
dam, the inlet canal including private property and along the west shoreline within the park after
those dates. When weather permits after November 1, many anglers fish from these areas within
the park. According to current regulations those anglers are in violation. It is believed that these
changes to allow fishing access will have minimal if any impact to waterfowl or waterfowl hunting
because these areas of the lake are closed to hunting for public safety reasons. Park staff will
designate boundaries within these areas for ice fishing. However, In recent years there has been
very little ice fishing activity on the lake.
Joe Wright Creek and Joe Wright Reservoir
 Remove current restriction on trout harvest
The previous regulation has led to public confusion since grayling are listed in the brochure
alongside trout. Grayling are overabundant in the reservoir and would benefit from some
increased harvest but many of the public have read the regulation to mean that harvest is not
allowed for grayling. The lake has become a destination fishery for grayling and the trout in have
become secondary in terms of both angling and management. It is our recommendation that the
bag and possession limit for trout be dropped from the special regulation but that the fly and lure
designation remain in place. Popularity of catch and release fishing has decreased harvest rates
statewide and we feel that Joe Wright would not have reduction in fishing quality by increasing
the possible harvest from two fish to four.
Lake Granby Tributaries
 Remove tributaries from all current special regulations on Lake Granby
10
Current regulations for Lake Granby extend to the headwaters of inlet (tributary) streams due to
the inclusion of “..including inlet streams…” in the title of the regulation. The current wording is a
carryover from previous concerns over migrating lake trout and attempts to protect them when out
of the reservoir. Lake trout regulations were changed in 2006 to allow a greater harvest and
concerns over protection of lake trout have diminished due to kokanee population issues.
Protection of lake trout in tributaries is no longer desirable.
Lon Hagler Reservoir
 Implement one-fish bag/possession limit and minimum size of 18 inches for bass
The existing population of bass in Lon Hagler Reservoir is dominated by 10-12 inch largemouth
bass which are not sexually mature at their current size. Age at length studies indicate
largemouth bass spawn in Colorado for the first time at roughly 15 inches or 4 years of age.
Results of fishery surveys at Lon Hagler found only 1 of 54 largemouth and 0 of 19 smallmouth
bass sampled exceeded 15 inches. Thus the population of brood-stock bass in Lon Hagler is
rather small. Accordingly, largemouth bass are potentially being harvested before completing a
single reproductive season in this reservoir. Besides poor natural reproduction, stunting by
bluegill and yellow perch populations have resulted from the lack of larger predators. Growth by
largemouth (Wr = 96) is not limited by available forage. Besides bluegill and perch, gizzard shad
significantly contribute to a sustainable forage base in this reservoir. Preliminary results from a
2010 creel survey indicates roughly 22,000 shore anglers and 4,000 boat anglers will take part in
fishing at Lon Hagler Reservoir during 2010. When asked, “…if you could catch any single
species which would you prefer?”, most anglers responded trout (70%), followed by bass (15%),
walleye (10%), catfish (4%) and sunfish (1%). All anglers surveyed (100%) support the existing
bass regulation. When asked if they would support an increase in the minimum length from 15
inches to 18 inches combined with a reduction in the bass limit, all anglers specifically targeting
bass (100%) answered yes. Anglers targeting trout were indifferent. Although no regulatory
action is required to bolster the trout fishery (90% angler satisfied), a regulation change can
significantly improve bass fishing at Lon Hagler Reservoir by increasing natural reproduction and
accommodating the large number of angler visits.
Long Lake, Lake Isabelle, South St. Vrain Creek
 Remove artificial flies and lures only regulation, two-fish limit on trout and timing closure
During the 1978-1981 period, creel census and lake surveys conducted by the Colorado Division
of Wildlife found Long Lake and waters immediately downstream were dominated by stunted
brook trout, white sucker, and longnose sucker. In an attempt to improve the fishery, Long Lake
was chemically treated with rotenone on September 8, 1984. Following the reclamation, Long
Lake was restocked with Emerald Lake rainbow trout. Special regulations were put into place to
limit harvest (2 trout) and hopefully establish a naturally reproducing population of the Emerald
strain (i.e. no fishing in the outlet stream). The project appeared successful as surveys
conducted in 1985 and 1986 found only Emerald rainbows. During 1987 and all subsequent
sampling years it was clear that brook trout had once again been established as the dominate
trout species in Long Lake. A 2008 survey sampled 170 brook trout and 1 rainbow/cutthroat
hybrid. The brook trout population in Long Lake is not stunted at this time. Several year classes
of brook trout were present with fish ranging in length from 4.1 to 15.7 inches; condition factor
averaged 90 (range 64 – 146). The regulation was later applied to protect the establishment and
spawn of native cutthroat trout (Colorado River and Greenback). Native cutthroat trout stocking
began in 2000 (34,454 fish stocked since 2000) but have failed to establish in Long Lake. Given
the failure of the reclamation to eliminate brook trout combined with the lack of establishment by
native cutthroat trout, we recommend applying general fishing regulations for Long Lake, Lake
Isabelle, and South Saint Vrain Creek between the headwaters and the inlet to Brainard Lake
(Figure 1). Increased harvest of trout from Long Lake is desired to avoid future stunting issues
and less desirable fishing opportunities. This will result in the elimination of Long Lake, Lake
Isabelle, and portions of South St. Vrain Creek from the list of waters with special fishing
regulations. Lake Isabelle, west of Long Lake, has an established population of greenback
11
cutthroat trout which is maintained through aerial stocking. Since 2000, 16,258 greenback
cutthroat trout have been stocked. This population does not appear to be self-sustaining as the
particular year classes of cutthroat trout correspond to years which Isabelle was stocked by DOW
pilots. In addition, cold water temperatures prevent natural reproduction at this elevation (12,000
feet). Given the lack of natural reproduction and limited fishing pressure, the special regulations
on this water should also be removed. Catch rates in Lake Isabelle were similar to other high
mountain lakes without special regulations.
Parachute Creek - East Middle Fork
 Implement cutthroat trout protection regulations
The East Middle Fork of Parachute Creek drains the Roan Plateau of Garfield County (northwest
of Rifle) in northwestern Colorado. This creek is home to 99% genetically pure Colorado River
cutthroat trout. The headwaters of the East Middle Fork of Parachute Creek include Trapper
Creek and Northwater Creek. Both of these waters also support 99% genetically pure Colorado
River cutthroat trout. Cutthroat trout Regulation #108 A currently applies to both Trapper and
Northwater creeks. The waters of the East Middle Fork of Parachute Creek drainage from its
headwaters (Trapper and Northwater creeks) to the East Middle Fork’s falls are also designated
and managed by the CDOW as cutthroat trout conservation waters. The Colorado River cutthroat
trout is the only species currently existing in Trapper, Northwater, and the East Middle Fork of
Parachute creeks. In addition, the CDOW maintains a broodstock of Trapper Creek cutthroat
trout in the Glenwood Springs Fish Hatchery. This broodstock has been used in Colorado River
cutthroat trout introduction programs for both conservation and recreation purposes. The majority
of the East Middle Fork of Parachute Creek drainage is located on BLM land, with the lower
portion of the creek (approximately 2.25 miles) downstream of the falls owned by Exxon Mobil
Corporation. Anglers can access the East Middle Fork of Parachute Creek via the BLM land on
the Roan Plateau. This drainage does not currently experience high angler recreation. However,
public land on top of the Roan Plateau is slated for energy development, pending the outcome of
current litigation processes. Private land on the Roan Plateau is currently being drilled for
energy purposes. The potential increase in development also correlates to the potential for an
increase in people moving into the area. The wildlife richness of the Roan Plateau may
encourage increased use by sportsmen, including that of the East Middle Fork of Parachute
Creek and anglers. The populations of 99% genetically pure Colorado River cutthroat trout that
inhabit waters of the Roan Plateau should be conserved and protected. The addition of the East
Middle Fork of Parachute Creek to this regulation will be consistent with its headwater streams.
Further, there is no biological basis for excluding this creek as a special regulation water when
the CDOW is managing this water and its headwaters as cutthroat trout conservation waters.
The current statewide bag (4 trout) and possession limits (8 trout) apply for cutthroat trout in the
East Middle Fork of Parachute Creek. Bait fishing is also allowed. We recommend the East
Middle Fork of Parachute Creek be considered a special regulation water, with artificial flies and
lures only, and all cutthroat trout caught returned to the water immediately.
Pastorius Reservoir
 Remove minimum size limit for largemouth bass
Pastorius Reservoir is a 53 acre, irrigation supply reservoir located just south of Durango. Water
level fluctuates throughout the summer irrigation season. The reservoir is often prone to winter kill
events. The reservoir is managed for catchable rainbow trout and pan fishing opportunities for
bluegill and largemouth bass. Cold water temperatures and short growing season limit the
growth of both bluegill and largemouth bass. The majority of bass collected during surveys range
in size from 3 to 5 inches in length. Few largemouth bass achieve the minimum length of 15
inches making the current regulation questionable. Allowing harvest of smaller bass will create an
environment where surviving bass recruit to larger size.
Piedra River
 Implement catch and release regulation for trout
12
The Piedra River is currently managed by special regulation #108B-269: Piedra River-Archuleta
County, a. From the Piedra River bridge on USFS 631 (Piedra Road) downstream to the lower
boundary of the Tres Piedra Ranch (1.5 miles above US 160): 1. Fishing is by artificial flies and
lures only, 2. The bag and possession limit for trout is two fish. Four major tributaries of the
Piedra River are found along this reach, each managed by statewide trout bag and possession
limits, offering harvest opportunities for the public. Despite the restrictive harvest regulation,
Piedra River does not consistently produce quality sized trout (14 inches or greater) that anglers
desire. Recent electrofishing surveys documented an average of 13 trout per mile over 14 inches
in length. For 22 years voluntary Angler Survey cards have been collected at three different
locations along this reach of the Piedra River. Angler satisfaction with the number and size of fish
dropped over the last 4 years. The most common, annual, unsolicited comment on these forms is
a request for a catch and release regulation. This 20 mile section of the Piedra is managed as a
Wilderness Area by San Juan National Forest and access is limited to a system of trails and few
trailheads. The river is popular among backpackers and horse packers. Suspected limiting
factors to the production of quality trout in the Piedra River include angler harvest, habitat and
otter predation. Eliminating harvest of trout by angling in this section of the Piedra River should
increase trout abundance and enhance the opportunity for anglers to catch quality sized trout.
Pikes Peak South Slope Recreation Area
 Implement special harvest restrictions for Boehmer Reservoir, Boehmer Creek, Mason
Reservoir and McReynolds Reservoir
Colorado Springs Utilities intends to open the South Slope Recreation Area (SSRA) for fishing.
These lakes have been closed for over 100 years, but have been used for several decades by the
DOW for cutthroat management. Springs Utilities has conducted a two year public review
process to develop a recreation management plan that has involved City staff, a citizen’s advisory
group, City Council, and extensive public and media review.
The recreation management plan is proposing that three lakes will be opened for public fishing,
including:
 McReynolds Reservoir (aka, Colorado Springs Water Supply Reservoir #5)
 Mason Reservoir (aka Colorado Springs Water Supply Reservoir #4)
 Lake Moraine
The first two lakes (as well as Boehmer Reservoir – see below) are currently closed to fishing by
DOW regulation (#108, 78), and have been used for recovery efforts for greenback cutthroat
trout, as well as a supplemental brood source for high lake cutthroat eggs. These two lakes are
on the Middle Beaver Creek drainage.
Lake Moraine has not been managed by the DOW, except for some transfers of fish from
McReynolds Reservoir over the years. Although not specifically closed by DOW regulation,
public access has been prohibited. This lake is within the Ruxton Creek drainage, which is
geographically separated from the other lakes.
Boehmer Reservoir (aka Colorado Springs Water Supply Reservoir #2) will not be opened for
public fishing, but will continue to be used exclusively for greenback cutthroat trout recovery.
The management plan for the SSRA is reaching completion, with the objective of providing
controlled public access and recreation while protecting water quality, utility infrastructure,
aesthetics, wildlife and fragile habitats.
Poage Lake
 Implement artificial flies and lures only and two trout limit with 12-inch maximum
Poage Lake is a productive high country lake capable of producing quality size trout and has long
been recognized by local anglers as a trophy cutthroat trout destination. The lake is managed by
statewide trout regulation and annual stocking of sub-catchable cutthroat trout. Over the past five
13
years anglers have commented at Angler Roundtable meetings about the lack of quality size trout
at Poage Lake. They requested DOW implement a special regulation that would restrict harvest
to create a quality trout fishing experience.
DOW sampling records since 2001 document abundant numbers of trout less than 13 inches
(78%), but few quality size trout greater than 16 inches in length (3%). The fishery management
goal is to increase the abundance of quality size trout (>16 inches) thereby providing a quality
fishing experience. Increasing the harvest of undersize trout will allow the survivors to grow to a
larger size. Therefore, we believe implementing a maximum size harvest limit will improve
recruitment of larger size trout to the population.
Rifle Gap
 Implement one-fish bag/possession limit for walleye
The CDOW currently manages Rifle Gap Reservoir as a mixed nonnative fishery, providing
anglers the opportunity to fish for both coldwater (rainbow and brown trout) and cool-warmwater
(walleye, smallmouth bass, yellow perch, northern pike, and black crappie) species. The walleye
and smallmouth bass fisheries within the reservoir have naturally sustained themselves since 1972
with the stocking of 200, 6” walleye and 6,325, 3” smallmouth bass. No walleye or smallmouth bass
have been stocked by the CDOW since 1972. Yellow perch, northern pike, and black crappie have
been illicitly introduced into Rifle Gap Reservoir since 1972. The CDOW believes yellow perch and
northern pike were illicitly introduced sometime between 1993 and 1999, while black crappie were
illicitly introduced sometime prior to September 1993. Currently, the CDOW only stocks catchable
rainbow trout into Rifle Gap. The reservoir is currently managed by the CDOW for coldwater trout
and cool-warmwater walleye and smallmouth bass.
The CDOW is currently limited to stocking only salmonids within Rifle Gap Reservoir, as the outlet of
the reservoir is not screened and salmonid species are not considered a primary threat to native
fishes downstream. Water released from the reservoir flows into Rifle Creek for approximately eight
miles until the creek joins the mainstem Colorado River. Rifle Creek transitions from a coldwater trout
fishery just downstream of Rifle Gap Reservoir to a cool-water native fish community at the
confluence with the Colorado River. The CDOW manages lower Rifle Creek and the Colorado River
downstream of the town of Rifle for native fishes, including listed and non-listed species (bluehead
sucker, flannelmouth sucker, roundtail chub, and speckled dace). The State of Colorado considers
the roundtail chub as a Species of Special Concern. The U.S. Fish and Wildlife Service has
designated the mouth of Rifle Creek and the mainstem Colorado River downstream of Rifle Creek as
critical habitat for four endangered fish species (humpback chub, bonytail, razorback sucker, and
Colorado pikeminnow).
The CDOW has secured funds from multiple sources to design and install an in-stream fish
screen in Rifle Creek downstream of Rifle Gap Reservoir in 2011. This screen will reduce
movement of nonnative sportfish from Rifle Gap Reservoir into Rifle Creek and critical habitat of
lower Rifle Creek and the mainstem Colorado River, thereby reducing negative interactions of
nonnative sportfish on native fish communities. Reservoir anglers will also benefit from the
screen as the CDOW will be allowed the opportunity to stock non-salmonid sportfish desired by
anglers and not currently stocked (i.e., walleye). The CDOW is working with anglers and other
stakeholders to revise the current Lake Management Plan for Rifle Gap Reservoir.
Anglers in the past have reported Rifle Gap Reservoir as a destination fishery in northwest
Colorado for walleye. The fishery in the 1970s and 1980s was comprised mostly of trout,
walleye, and smallmouth bass (Figure 1). Illicit introductions primarily of yellow perch and
northern pike between 1993 and 1999, however, have drastically changed the fisheries
composition of Rifle Gap Reservoir. In 1993, walleye comprised 51% of the fishery based upon
fall sampling methods. By 2002, yellow perch constituted nearly 50% of the fish species
composition in Rifle Gap Reservoir. The most recent data from 2009 indicate 2/3 of fish collected
in Rifle Gap Reservoir consisted of yellow perch. Northern pike have also increased their
14
presence within the reservoir, constituting <1% of fish species collected in 2002 and increasing to
4% in 2009. This percentage may not seem very significant but northern pike are considered top
level predators. Prior to the introduction of northern pike, walleye were the only top level
predators present in Rifle Gap Reservoir.
The ever changing fishery at Rifle Gap Reservoir has resulted in the decline of the walleye fishery
over time. Several major conclusions can be derived from the routine fishery sampling data and
the 1987 and 2009 open water creel data presented above regarding the walleye fishery in Rifle
Gap Reservoir. These include:
1) the fishery composition and fish species available to anglers in Rifle Gap Reservoir have
changed over time; more species and more fish are present; 2) total number of walleye available
to anglers has decreased; 3) length of walleye has increased over time indicating no recruitment
of juvenile walleye to small, adult walleye; 4) walleye are still preferred by anglers with some
limited harvest occurring (<14% of walleye caught were kept). Therefore, these regulations
modify the existing bag and possession limit for walleye from three fish at 18” to one fish at 18”.
River Center Ponds
 Adjust harvest restrictions to mirror those on the San Juan River
A two-mile section of the San Juan River flowing though the town of Pagosa Springs is regulated
by a two-fish bag and possession limit (#108B- 318. San Juan River - Archuleta County; a. From
the intersection of US 160 and US 84 downstream through Pagosa Springs to the intersection of
Apache Street with the river: 1. The bag and possession limit for trout is two fish). In order to be
consistent with the San Juan River fishing regulation, the town of Pagosa Springs has placed the
same bag and possession limit on the River Center Ponds which are connected to the San Juan
River. The Town of Pagosa Springs and Division of Wildlife periodically stock the ponds with
trout. Some trout enter (and exit) the ponds from the nearby river. Because the current
regulation (#108B-318) in the CDOW Fishing Brochure does not include the River Center Ponds
some anglers are confused about the distinction between the two bag and possession limits.
Anglers are unsure whether they can have four fish in possession (two from the river and two
from the pond). This poses a law enforcement problem. Including the River Center Ponds into
the current special regulation on the San Juan River (#108B-318) is intended to address this
issue.
St. Vrain State Park
 Bald Eagle Lake - Add smallmouth bass to the already-existing catch and release
regulation for largemouth bass
Bald Eagle Pond, located within Saint Vrain State Park, is managed as a trophy catch and
release bass fishery. To eliminate ambiguity based on discrepancies in bass identification we
propose adding smallmouth bass to the list of species protected from harvest at this pond.
Smallmouth bass are typically not stocked in Bald Eagle Pond however; many anglers find it
difficult to distinguish the differences between smallmouth and largemouth bass, which are
protected. The goal of the original regulation was to protect all bass from harvest in the pond.
St. Vrain State Park
 Blue Heron Lake - Add minimum bass size of 21 inches with bag/possession limit of one
fish
Once full, Blue Heron Lake will provide exceptional habitat for black bass and variety of other
warmwater fish species. In addition, this 82-acre reservoir will significantly diversify fishing
opportunities at Saint Vrain State Park by allowing access to boat anglers (electric motors only).
Currently Saint Vrain State Park offers anglers nine individual ponds available for fishing.
Although all ponds within the park contain largemouth and/or smallmouth bass, five ponds are
15
managed for put and take trout fishing; three are managed for catfish/bluegill, while only one
pond is managed exclusively for bass fishing (Bald Eagle Pond).
Once filled, Blue Heron pond will likely attract the lion’s share of the warmwater fishing pressure,
and may represent the focal point of appreciable day-use visits with the sole purpose of fishing.
To accommodate the anticipated heavy use (127,000 angler visits in 2008) on Blue Heron Lake
and continue to diversify fishing opportunities in the park, this regulation is intended to limit the
harvest of largemouth and smallmouth bass.
Sweitzer Lake
 Implement a regulation requiring catch and release for all fish
Sweitzer Lake is a 137-acre warmwater fishery containing green sunfish and common carp.
Because of water quality problems from the underlying geology and the irrigation return flows that
feed it, the lake has elevated levels of selenium. The Colorado Department of Public Health and
Environment has issued the following advisory: The general population is advised to not consume
any fish from these waters. Recent sampling has indicated that fish tissue concentrations of
selenium are still above the recommended limit, but not as high as those reported when the
advisory was first put in place and water quality is sufficient to support viable sport fish
populations. Currently the DOW does not actively manage the fishery in Sweitzer due to
concerns about creating a fishery that would attract people who could ignore the advisory. With
the lack of good warm water fishing opportunity on the west slope and the desire of anglers for
this opportunity, we would like to develop a catch and release warmwater fishery for popular
species like largemouth bass and/or tiger muskie. The fishery could be managed to provide
trophy fishing opportunity to anglers and the new regulation would formalize the consumption
advisory into an enforceable regulation and allow us to develop a fishery without creating an
attractive nuisance to anglers. A new regulation mandating catch-and-release angling would
allow us to move forward with a new lake management plan exploring increased fishing
opportunity while carefully monitoring water quality trends studying and fish tissue contaminants.
The local angling public has repeatedly expressed the desire for expanded warmwater fishing
opportunity and Sweitzer Lake is an underutilized resource that could potentially provide
significant new fishing opportunity without any negative impacts to downstream native fish.
Teller Lake #5
 Remove minimum size restriction for bass
Teller Lake #5, located in Boulder County, is an extremely shallow lake which provides very
limited sport fishing opportunities. A fishery survey completed in 2005 found common carp
comprised 30% of all species sampled while an additional survey completed in 2010 determined
carp comprised nearly 70% of the fish community. The July 2010 survey found that angling
opportunity significantly decreased since the 2005 survey. Despite stocking 3,000 fingerling bass
every year since 2001, largemouth bass made up less than 2% of the catch in 2005 and 2010
with no bass exceeding 10 inches. Habitat conditions and natural reproduction by bass in the
lake are extremely poor. Given the poor quality of Teller Lake #5 natural features and very
limited success of bass in this water the special regulation which limits the harvest of smallmouth
and largemouth bass under 15 inches has been removed.
Trinidad Reservoir
 Remove minimum size restriction and modify to one fish per day greater than 18 inches
for walleye
In 2006, the walleye/saugeye regulation at Trinidad Reservoir was changed to improve the quality
of the fishery by restricting harvest to 5 fish larger than 15” of which only 1 fish could be over 21”.
However, in January 2007 a Fish Consumption Advisory (FCA) was issued by the Colorado
Department of Public Health and Environment (CDPHE) on walleye and saugeye greater than 18
inches in length due to exceedance values for mercury. Fish were again tested for mercury
16
levels in 2008 which indicated mercury levels at or near exceedance values for walleye larger
than 18”. In addition, population sampling, angler catch, and walleye tournament data shows that
the walleye fishery is currently out of balance with the forage – i.e., a very limited shad population
and excessive number of small (<15”) walleye that are in poor condition with limited growth
potential.
While the fishing regulations allow harvest of larger (>15”) fish, those larger fish are also most
likely to contain higher levels of mercury. This puts the quality fishing regulations at odds with
human fish consumption concerns. At the same time, a lack of gizzard shad forage has reduced
the condition and growth of the numerous small walleye which are then less able to grow to
quality size. Anglers are generally disappointed in the walleye fishing, particularly for larger fish.
The draft recommendation proposes a fishing regulation that would provide an opportunity for
harvest of smaller fish (that are not under a FCA) while still maintain fishing for quality-sized
walleye/saugeye.
Western Slope Rivers
 Remove harvest restrictions for nonnative fish for some rivers
To aid in the recovery of the four federally listed fish species found in big rivers on the western
slope, the bag and possession limits were removed in 1996 for the following species within
federally listed critical habitat: channel catfish, largemouth bass, smallmouth bass, northern pike,
walleye, green sunfish, bluegill, bullhead, yellow perch and crappie.
These species have become more common over the years and their impacts on native fish
species has become more widely recognized. Proliferation of these species higher in the
drainages and their movement downstream has been recognized as a factor contributing to the
decline of non-endangered native fishes. Extension of the no bag and possession limit
regulations to the headwaters of some river systems is a step forward in limiting the future
impacts of nonnative fish, and an acceptable way of enlisting angler support in maintaining
sustainable stocks of native species.
Affected Rivers are as follows:
NW Region
 Colorado River
 Eagle River
 White River
SW Region
 Animas River
 Blanco River
 Dolores River
 Florida River
 Gunnison River
 Gunnison River (North Fork)
 La Plata River
 Los Pinos River
 Mancos River
 McElmo Creek
 Navajo River
 Piedra River
 San Juan River
 San Miguel River
 Uncompahgre River
17
Yampa River
 Implement seasonal fishing closure between Stagecoach Reservoir and Catamount Lake
Whirling disease (WD) is a malady of trout and salmon caused by the microscopic parasite
Myxoboilis cerebralis. Whirling disease was first detected in Colorado in 1988 and has since been
a major factor in significant declines of wild trout populations throughout the state. High levels of
WD infectivity were detected in the section of the Yampa River below Stagecoach Reservoir in
2002. Annual surveys in 2006 revealed multiple missing age classes and an inevitable population
crash. This tailwater section of the Yampa River receives a tremendous amount of angling
pressure, especially during the spring months. In an effort to rehabilitate this high use fishery, we
began stocking WD resistant rainbow trout in 2006. Coinciding with this, we collaborated with
State Parks to reduce angling pressure throughout this reach. This is one of very few remaining
pure rainbow trout fisheries in the State of Colorado; therefore, very important from a research
perspective. The overarching question being, can we achieve a natural reproducing rainbow trout
fishery in waters of elevated WD infectivity levels, and absent competition from other salmonids
such as brown trout? Truly a unique opportunity in the State of Colorado.
Relevant factors influencing fry recruitment were evaluated, and given the recent stocking of WD
resistant rainbow trout, the remaining unknown is the impact of angler wading on redds during
high spring use, which coincides with spawn activities. Rainbow fry production has been
monitored annually since 2003, and in spring 2008 voluntary closures of individual redds were
implemented. These individual closures were labor intensive to maintain and compliance issues
were realized. However, subsequent sampling revealed an increase in fry production. In 2009, no
closures were implemented and follow-up sampling revealed a decrease in fry production. It has
been deemed necessary to have the ability to initiate an official closure, in alternating years
initially, in an effort to study angler wading impacts on redds. If studies indicate a need for
additional protection, then an annual closure may be appropriate, and implemented through
posting.
The statutory authority for these regulations can be found in § 24-4-103, C.R.S., and the
state Wildlife Act, §§ 33-1-101 to 33-6-209, C.R.S., specifically including, but not limited to:
§§ 33-1-101, 102, 104, 105, 106-108, 115, and 121; §§ 33-2-104, 105, 106, and 107; § 33-3104; §§ 33-4-101, 102, 102.5, 103, 116, 116.5, 117, and 119; § 33-5.5-102; and §§ 33-6-107,
109, 112, 113, 113.5, 114, 114.5, 117, 119, 120, 121, 124, 127, 128, 129, 131, 205, 206, 207,
and 208.
EFFECTIVE DATE - THESE REGULATIONS SHALL BECOME EFFECTIVE JANUARY 1, 2011
AND SHALL REMAIN IN FULL FORCE AND EFFECT UNTIL REPEALED, AMENDED OR
SUPERSEDED.
APPROVED AND ADOPTED BY THE WILDLIFE COMMISSION OF THE STATE OF
COLORADO THIS 12th DAY OF NOVEMBER, 2010.
APPROVED:
Tim Glenn
Chairman
ATTEST:
Mark Smith
Secretary
18