Rio Grande cutthroat trout (RGCT; Oncorhynchus clarkii virginalis); Westslope cutthroat trout (WCT; Oncorhynchus clarkii lewisi)

Principal Biologist(s)

Carter Kruse, Eric Leinonen

Project Location

Costilla Creek, Vermejo River, Vermejo Park Ranch – RGCT
Las Animas Creek, Ladder Ranch – RGCT
Cherry Creek, NF Spanish Creek, Green Hollow Creek, Flying D Ranch – WCT
Greenhorn Creek, Snowcrest Ranch – WCT

Project Partners

New Mexico Department of Game & Fish
Colorado Parks & Wildlife
Montana Department of Fish, Wildlife & Parks
US Forest Service
US Fish & Wildlife Service
Bureau of Land Management
Trout Unlimited

Conservation Problem

Range-wide declines are due to competition and introgression with introduced salmonids, as well as habitat degradation and exploitation. Westslope cutthroat trout (WCT) were historically the most widespread cutthroat subspecies, occupying around 90,800 km of streams and rivers of the upper Columbia and Missouri basins of Montana, Wyoming and Idaho. The historical range of genetically pure populations has been reduced by 76%. On the east side of the Continental Divide range reduction has been most dramatic, exceeding 95%. Rio Grande cutthroat trout (RGCT) were historically found in about 10,700 km of habitat in the upper Rio Grande basin of Colorado and New Mexico. The distribution of genetically pure populations of this subspecies has been reduced by 92%.

Conservation Status

• RGCT are a Species of Greatest Conservation Need by NMDGF and CPW.
• WCT are a Species of Greatest Conservation Need by MTFWP.
• Both subspecies have been petitioned for ESA listing, but found not warranted for listing.

Project Recognition

• 2005 MT AFS – Collaborative Group Award
• 2010 USFS – Collaborative Aquatic Stewardship Award
• 2011 Western Division AFS – Conservation Achievement Award
• 2012 American Fisheries Society – President’s Fishery Conservation Award
• 2015 Governor’s (NM) Environmental Excellence Award for Wildlife Conservation
• 2016 Sustaining Forest and Grassland Award, US Forest Service Region 1

Project Goals

We aim to restore or enhance self-sustaining populations of native cutthroat trout on Turner Ranches and surrounding landscapes to improve the conservation status of subspecies. We also aim to contribute information on cutthroat trout to the scientific community to improve our understanding of these subspecies and their conservation status.


Over a two-decade period, TBD will lead or catalyze restoration or improvement of native cutthroat trout stocks in 400 km of stream within the interior Rocky Mountain west to advance the conservation and recovery of the species; serve as a model for large scale conservation efforts on private landscapes; and contribute to conservation science through innovation, implementation and research in the field. Cutthroat trout restoration and conservation projects will include at least two subspecies of cutthroat trout, be implemented in at least 6 sites, and include at least one meta-population (multiple, connected streams) restoration effort per subspecies. Restored populations will be allopatric and exhibit minimum mean densities of 100 adult (i.e., > 120 mm total length) fish per kilometer with successful recruitment (i.e., young-of-year fish or multiple age/size classes present) at least once every three years. TBD will work with state and federal partners to advance species conservation and recovery by implementing research and monitoring opportunities that result in publication of at least five peer reviewed scientific articles.

Project Background

Range-wide conservation agreements among management agencies and non-governmental organizations are in place to guide conservation and restoration activities for WCT and RGCT across jurisdictional boundaries. Objectives outlined in these documents include: securing and monitoring known cutthroat trout populations; seeking opportunities to restore or found new populations, especially over large areas and including private lands; identifying or locating any additional wild populations; coordinating conservation activities among resource agencies and non-governmental organizations; and providing public outreach and technical assistance. These range-wide objectives for cutthroat trout conservation are consistent with the mission of Turner Enterprises and fit within the land management framework on the Turner Ranches. Most importantly, the Turner family has been supportive of cutthroat restoration, embracing the risks inherent with large-scale native trout restoration. The TBD program developed a Cutthroat Trout Initiative to catalyze cutthroat restoration or conservation activities on 400 km of stream. This is by far the most comprehensive and ambitious private effort on behalf of native cutthroat trout. Efforts to restore or conserve cutthroat trout are in underway in seven streams on four ranches. The overall goal is to improve the range-wide status of RGCT and WCT and prevent listing under ESA using the following strategy:

• Selection of reintroduction sites encompassing a large geographic area with high quality and diverse habitats to support robust cutthroat trout populations with diverse life-history strategies that are able to resist threats such as climate change, catastrophic events, and invasive species
• Elimination of non-native competitors in the reintroduction site through physical and/or chemical renovation and prevention of their recolonization
• Establishment of a self-sustaining population of cutthroat trout large enough to withstand environmental and demographic stochasticity and likely to persist over the long-term (>100 years) with little or no human intervention
• Establishment of a monitoring strategy, including relevant research partnerships, that evaluates key project aspects and allows adaptive management as the project unfolds to improve and guide future efforts

The cutthroat trout is native to the Rocky Mountain and coastal areas of the western U.S. and is classified into as many as 14 subspecies. The seven major inland subspecies of cutthroat trout historically occupied most accessible cold-water environments from Canada to southern New Mexico. However, all subspecies have incurred significant range reductions primarily due to competition and introgression with introduced salmonids, as well as habitat degradation and exploitation. Lahontan (O. c. henshawi) and greenback (O. c. stomias) cutthroat trout are listed as threatened under the ESA and the other inland subspecies have either been petitioned for listing under the ESA or are considered species of concern by state and federal agencies. Recovery and conservation efforts are underway for all major subspecies, with many notable successes; however, such efforts are hindered by ongoing non-native invasions, limited opportunities for large-scale projects, social resistance, changing habitat conditions (e.g., climate change), and past, widespread introductions of cutthroat trout subspecies outside their native ranges.

The Turner organization and ranches are ideally situated to play an important role in cutthroat trout conservation. The Flying D, Snowcrest, Vermejo, and Ladder ranches all contain large, connected sections of high-quality cold-water stream habitat within the historical range of WCT and RGCT. In conjunction with neighboring public lands these ranches encompass entire stream headwaters, an important consideration when prioritizing and securing restoration sites. Although small restoration projects (e.g., <15 km of stream) are important to preserve presence and genetic variability on the landscape, cutthroat conservation projects most likely to succeed over the long-term are those encompassing large areas that connect multiple, local sub-populations and allow expression of multiple life histories, thus creating a better chance of withstanding localized extinctions and changing habitat conditions.

Through the RGCT and WCT Range-Wide Conservation Working Groups, TBD has partnered with public agencies and other private organizations to implement two of the largest cutthroat trout restoration projects ever undertaken in the United States.

Cherry Creek – Planning for the Cherry Creek Native WCT Project on the Flying D Ranch was initiated in 1997. Logistical and legal issues delayed field work (e.g., piscicide application) until 2003. Chemical application was completed in 2010 and restocking by 2014. The project encompasses approximately 100 km of stream habitat and 3 ha of lake suitable for cutthroat trout and is the largest piscicide renovation project ever completed for the purpose of cutthroat trout conservation to date.

Introductions of WCT into Cherry Creek were done primarily by stocking eyed eggs into remote streamside incubators (RSIs). Approximately 37,000 eyed eggs were stocked into RSIs from 2006-2010 which resulted in 27,000 surviving fry. Another 8,850 hatchery-reared fry were stocked into the lower portions of the project area (e.g., the Butler Reach), along with about 6,500 age-1 triploid WCT. This was the first time triploid WCT had been successfully produced and stocked into Montana waters. Annual monitoring of the restored WCT population from 2012-18 showed that the numbers increased rapidly post-treatment and is now similar to pre-treatment population abundance and average size. The WCT population in Cherry Creek exceeds a conservative estimate of 50,000 individuals.

The Cherry Creek project is a significant conservation achievement for WCT on the east side of the Continental Divide. This project increases the extent of stream occupied by WCT in the Madison River basin from 7 km to over 100 km (or from 0.3% of historical occupancy to almost 5%). On an even larger scale, prior to the Cherry Creek project, WCT occupied an estimated 750 km (4.2%) of their historic range in the Missouri River Drainage; nearly all of these populations were in 1st or 2nd order streams, restricted to 8 km of habitat or less, and with flows of 0.08 m3/s or less. The Cherry Creek project increased occupied habitat by 100 km and included a 4th order watershed with as much as 0.57 m3/s stream flow. Perhaps more importantly, the success of, and lessons learned from, the Cherry Creek project has catalyzed several other cutthroat trout reintroduction projects in southwestern MT and across the region. For example, by 2015, WCT occupied an estimated 1,030 km (5.8%) of historical range in the Missouri River Drainage due to restoration activities. MTFWP has conducted annual mark-recapture electrofishing population estimates in a 6.4 km section of the Madison River immediately adjacent to the Cherry Creek confluence since 1967 to monitor naturalized populations of rainbow trout and brown trout (Salmo trutta) in the river. Few, if any, cutthroat trout were historically captured in this section. MTFWP began capturing WCT in 2012, and in March 2016, captured 130 WCT between 180 and 360 mm. Anglers are now pursuing WCT in the river and reporting their catches to FWP. In 2016, anglers reported catching WCT in the river as far as 37 km downstream of Cherry Creek.
A Candidate Conservation Agreement with Assurances (CCAA) regarding the Cherry Creek project was signed in 2009. This established that if TBD allowed WCT to be restored in the Cherry Creek project area, TEI would not be held to additional regulatory obligations if WCT were listed under ESA in the future. Further, the document preemptively permits incidental take of WCT that may occur during regular ranching or recreational activities if the species was listed.

Five graduate students have worked on the Cherry Creek project and nine scientific articles have been published in the North American Journal of Fisheries Management, Transactions of the American Fisheries Society, and Restoration Ecology. Research and monitoring regarding genetic variability, growth, survival, and movement of the recovering WCT is ongoing.

Through the RGCT and WCT Range-Wide Conservation Working Groups, TBD has partnered with public agencies and other private organizations to implement two of the largest cutthroat trout restoration projects ever undertaken in the United States.

Costilla Creek – The Costilla Creek Native RGCT Project on Vermejo Park Ranch (VPR) in New Mexico and Colorado is the most ambitious watershed renovation project ever initiated on behalf of any cutthroat trout to date, encompassing approximately 175 km of stream habitat (60% on VPR, remainder on Carson National Forest) and 18 lakes (all on Vermejo). Fieldwork on the Vermejo portion of the project was initiated in 2002 and completed in 2016 with the 2nd treatment of Costilla Reservoir. Restocking of RGCT is ongoing. When fully implemented by 2020 the project will represent a 20% increase in the amount of stream occupied by genetically pure RGCT within their historical range.

This project would not have been initiated without Turner support and is the flagship restoration effort on behalf of RGCT for the NMDGF. Planning and implementation of the Costilla Project is largely responsible for the development of consistent NM state guidelines regarding the use of piscicides and for re-development of NMDGF native cutthroat trout hatchery brood stock, both important steps for range-wide conservation of the species.

Monitoring is conducted on an annual basis and suggests that RGCT populations in the upper portions of the project area are similar in size and abundance to pre-project levels (e.g., upper Costilla and Casias creeks) despite three different rotenone applications since 2002 and are recovering in more recently treated areas (e.g. lower Costilla and Casias creeks, and Costilla Reservoir).

A CCAA regarding the Costilla Creek project was signed in 2013. Similar to the Cherry Creek project, this CCAA document recognizes the conservation actions implemented by TBD on behalf of RGCT and provides operational assurances to VPR should the species become listed under ESA.

Vermejo River – This is the only project in the Cutthroat Trout Initiative where aboriginal cutthroat trout are known to remain on Turner Ranches. This conservation population of RGCT is threatened by competition with nonnative brook trout (Salvelinus fontinalis), hybridization with rainbow trout (O. mykiss), and declining habitat quality (e.g., increased stream temperatures and turbidity). In an effort to maintain the population, TBD removed approximately 29,000 brook trout from the upper 36 km of the Vermejo River from 2010-16. More importantly, 20 confirmed rainbow/cutthroat trout hybrids and 1 rainbow trout (from Leandro Creek in 2015) were removed from the watershed from 2010-15. The source of this low-level rainbow trout invasion was unknown, but unscreened fishing ponds on upstream neighbors were initially suspected. Unfortunately, in 2016 an additional five rainbow trout and 15 hybrids were found in Leandro Creek. These fish were almost certainly the result of rainbow trout escaping from Vermejo’s fishing lakes via overflow. A focused effort was made in 2017 to detect and remove rainbow and hybrid rainbow/cutthroat trout from Leandro Creek. In 2017, a 15 km section of Leandro Creek was intensively shocked to remove all brook trout, as well as any other fish two years old or younger (e.g. potential hybrids). With this effort 1,548 brook trout were removed, 560 adult RGCT were captured and released, and 630 young rainbow, cutthroat, and/or hybrid trout were removed. A subsample of 63 young fish (10%) was genetically tested and 23 were confirmed hybrids. Thus, we estimate that up to 230 cutthroat/rainbow hybrids were removed from Leandro Creek. VPR has been encouraged to monitor lake water levels more closely and screen lake outlets to prevent escape. TBD is working with VPR on a more permanent solution for conservation of cutthroat trout in the Vermejo River, which might include future piscicide renovation. So far, physical removal of non-native or hybrid trout has helped keep the genetic status of Vermejo River RGCT at least 99% pure, but it is an unsustainable activity over the long term and a more permanent resolution to the hybridization issue is needed.

In 2017, TBD and VPR agreed to a proposal from NMDGF to stock YY brook trout males into two small creeks (Bernal and Leandro) as part of an experiment to determine if a high proportion of artificially derived YY males stocked into a population can drive it to extinction by producing only normal XY male offspring. A successful outcome could provide an alternative to chemical removal of brook trout.

Drought cycles and chronic over browsing by wildlife and livestock have negatively impacted the riparian habitat along the upper Vermejo River. Reduced riparian vegetation and limited woody plant recruitment have destabilized banks and impacted water quality to the detriment of native fishes and riparian obligate species. In 2014 and 2015, TBD received $141,000 in grants (50% cost share) from New Mexico Partners for Fish and Wildlife (US Fish and Wildlife Service) to construct ten .5 mi long x 8 ft high exclosure fences along sections of the upper Vermejo River. The fences are designed to exclude large ungulate grazing. Two exclosures were completed in 2014, four more in 2015, and two additional in 2016. Construction of the final two fences occurred in 2017. Ultimately, the goal is to enhance riparian conditions over the next decade and restore beaver (Castor canadensis) to promote long-term riparian health, RGCT persistence, and natural water storage in the upper Vermejo system. Monitoring of improvements inside the exclosures is underway and includes vegetative photo points, water temperature measurements, fisheries surveys, and macroinvertebrate collections.

Las Animas Creek – This project was undertaken to restore the native fish community (i.e. RGCT, Rio Grande sucker, and Rio Grande chub) to the upper 48 km of Las Animas Creek. Approximately half of the project area is located on the Ladder Ranch, with the remainder on the Gila National Forest. All three species are of conservation concern and have been petitioned for listing under ESA. (RGCT were determined to be not warranted for listing in 2014.) This project has experienced administrative and political delays since its conception in 1998; however, more recent momentum led to a draft environmental assessment (DEA) by the USFS for the project in early 2014. The DEA concluded a rotenone treatment to remove non-native longfin dace (Agosia chrysogaster) and hybridized rainbow/Yellowstone cutthroat trout from the project area was the best option to restore the native fish community. However, while the DEA was under development the 138,000-acre Silver Fire burned the entire Gila National Forest portion of the watershed in summer 2013. Subsequent monsoon rains resulted in multiple, significant debris, sediment, and ash flows, drastically changing the instream habitat. Population surveys in 2014, 2015, and 2016 indicate that the fire and its aftermath killed or displaced most of the fish in the project area. Non-native longfin dace survived in off-channel refugia not impacted by debris flows and are repopulating the project area. Limited numbers of Rio Grande chub were also observed for the first-time post fire in 2016. Hybrid trout and Rio Grande sucker were extirpated by the effects of the fire. Subsequently, NM Department of Game and Fish and TBD have decided not to conduct a rotenone treatment to remove the longfin dace. A 2016 watershed assessment indicated that instream habitat is sufficiently recovered to support a small population of RGCT.

NF Spanish Creek – WCT are nearly extinct in the Gallatin River watershed. Restoring WCT to ~30 stream km in upper NF Spanish Creek would be a significant conservation gain and establish an important beachhead for additional WCT restoration in the Gallatin watershed. Currently only 0.5% of historical stream habitat (1,690 km) in the Gallatin watershed contains genetically pure WCT. The majority of this project is on public land, thus MTFWP and the USFS administered the public scoping and EA process. A public scoping letter was published in early 2016 and an EA was drafted. The EA was approved by MTFWP in July 2017 and USFS in February 2018. Design of a fish barrier to protect the restored WCT population was completed in 2016, and the bid for construction was $430,000. Fundraising efforts for the barrier raised sufficient funds from eight partners: NFWF, MT Future Fisheries, Western Native Trout Initiative, USFS, TBD ($40,000 of total), TU, Northwestern Energy, and the MTTF.

Greenhorn Creek – This 32 km project area, including the NF and SF of Greenhorn Creek, was successfully treated with rotenone in July 2013 and 2014. Project partners conducted extensive electrofishing and eDNA surveys in 2015 to determine if non-native trout persisted. The detection and removal of a single brook trout delayed introduction of WCT until 2016. In August 2016, Greenhorn Creek was stocked via a wild transfer of 315 adults from six remnant populations of WCT in the upper Missouri River Basin. 318 additional WCT from the same six sources were stocked in 2017. Monitoring of WCT recovery in Greenhorn Creek is ongoing. Once a viable population of WCT recovers, this project will represent the largest population of WCT in the Ruby River watershed.

Green Hollow Creek – To reduce disease and competitive pressures on the Green Hollow II Arctic grayling conservation brood stock, TBD has removed brook and rainbow trout from upper Green Hollow Creek since 2003. Since 2006, only brook trout have been captured. In 2010, the focus of the program shifted from reduction to elimination in anticipation of reintroducing WCT to upper Green Hollow Creek (above Green Hollow Reservoir II), with removals conducted as scheduling allows. The number of fish removed to-date is 14,857, and annual catch has been less than 100 individuals for the past three years, down from a high of over 3,500 fish in 2012. Efforts will continue over the next 3-5 years to remove all brook trout from upper Green Hollow Creek. MTFWP is exploring upper Green Hollow as a potential refugia site for Gallatin Drainage WCT stocks.

Project Activities in 2018

Cherry Creek Activities – After reaching an all-time high abundance in 2015, electrofishing at long term monitoring sites in 2018 indicated that WCT numbers remain higher than the pretreatment average. A typical fish in Cherry Creek is about 180 mm (7.5”), consistent with the long-term average. Conservative estimates put the population at a minimum of 50,000 fish. Not surprisingly then, anglers reported high catch rates on Cherry Creek in 2018. No non-native trout have been captured in the project area since piscicide treatments were completed in 2010. Monitoring and recapture of tagged fish continues to provide data on survival, movement, growth, and genetic fitness of the population, although this work was scaled back in 2018. Several scientific manuscripts are under preparation, including a capstone book chapter tentatively entitled “Collaborative Eradication of Non-native Trout and Introduction of Native Westslope Cutthroat Trout into 100 km of Cherry Creek, a Madison River, Montana, Tributary” that will be published in 2019. TBD maintained a partnership with University of Idaho to assist with genetic analyses. Yellowstone National Park requested and was granted permission to collect WCT eggs from Cherry Creek for restoration projects in the park.

Costilla Creek Activities – We continued to focus on RGCT population recovery in the reservoir and lower portions of streams treated for the last time in 2016. Approximately 338,000 RGCT were stocked in the project area in 2018. A large portion of these were age-0 fish put into Costilla Reservoir (~266,000), but additional age 0-2 fish were stocked into lower Costilla and Casias creeks.

Guides and guests reported that angling was good in the project area in 2018 even though the population is still recovering in the reservoir and lower stream reaches. Population monitoring continued in the upper portions of the watershed and the data continue to show that fish abundance and size have recovered to pre-project levels. No non-native trout were detected during population monitoring with electrofishing and environmental (e)DNA samples also did not detect any non-native trout presence, providing additional evidence that the treatments were successful. Permitting for removal of the temporary fish barriers installed to facilitate treatment was completed and barrier removal will begin in 2019.

Vermejo River Activities – It was a very low water year in the Vermejo watershed. To prevent escapement of rainbow trout into the Vermejo River, VPR fabricated and installed fish screens on the outlets of Munn and Bernal lakes.

Monitoring was conducted throughout the drainage in 2018 and TBD crews removed four additional suspected hybrid rainbow/cutthroat trout from the watershed. Vegetative photo points, water temperature measurements, fisheries surveys, and macroinvertebrate collections were conducted to assess the impacts of the 10 riparian exclosures. A proposal was submitted to USFWS to build two more grazing exclosures along Leandro Creek. TBD was excited to see a large beaver dam on Ricardo Creek inside one of the first two exclosures built in 2014. A culvert fish barrier was installed on Leandro Creek to isolate upper Leandro Creek to facilitate the YY brook trout study. A graduate student from NMSU collected pre-stocking fish data and then YY brook trout were stocked into Leandro Creek above the barrier.

Las Animas Creek Activities – Electrofishing surveys in 2018 continued to confirm the extirpation of non-native hybrid trout and native Rio Grande sucker due to the 2013 Silver Fire, as well as the robust recovery of non-native long fin dace and a slower recovery of native Rio Grande chub in Las Animas Creek. NMDGF stocked another 150 RGCT from Canones Creek into upper Las Animas Creek on the Gila National Forest in May 2018, in addition to the 48 stocked in 2017. This will provide an important replicate and genetic reservoir for that population. TBD captured and moved 325 Rio Grande suckers from Palomas Creek on the Ladder Ranch into two locations on Las Animas Creek to re-found the extirpated sucker population. Sixty Rio Grande chub were also stocked into Las Animas Creek to supplement the recovering chub population.

NF Spanish Creek Activities – TBD continued to gather pre-treatment baseline information using electrofishing surveys at standard sampling sites to map fish distributions throughout the watershed. The $430,000 fish barrier was constructed in August and September by Bairco Construction of Lovell, WY. Several logistical planning meetings were held with USFS and MTFWP. Initial piscicide treatments are scheduled start in August 2019.

Greenhorn Creek Activities – An annual inspection was conducted on the Greenhorn fish migration barrier. In August of 2018 Greenhorn Creek was stocked for the third consecutive year (315 fish in 2016; 318 fish in 2017) via a wild transfer of 50 adult fish from six remnant populations of WCT in the upper Missouri River Basin. No additional introductions are planned unless future population monitoring indicates a need for additional fish. No population monitoring was conducted in 2018, but TBD is funding a graduate student through the University of Montana to look at genetic diversity and population demographics in Greenhorn Creek starting in 2019.

Green Hollow Creek Activities – Limited effort was spent capturing brook trout. Only 28 fish were removed.

Proposed Future Activities

Over the past decade, TBD has developed both capable partnerships and considerable field expertise that, with a little luck, should drive the Cutthroat Trout Initiative to a successful conclusion. All the cutthroat trout restoration and conservation projects described herein have substantial momentum, and with the exception of work in the Vermejo River, should be completed by 2020. No additional cutthroat trout restoration projects are planned for Turner properties. With exception of the Bear Trap Creek project, which was removed from consideration for native trout restoration in 2015, TBD has remained committed to the vision established by the Cutthroat Trout Initiative over 18 years ago. Our partners appreciate the resources, commitment, experience, and steady hand the Turner organization brings to a project. Successful conclusion of the Cutthroat Trout Initiative establishes a legacy the Turner organization can be proud of.