Rawlins Field Office

Colorado River Cutthroat Trout Reintroduction

History

Colorado River cutthroat trout

The Colorado River cutthroat trout (CRCT) historically occupied portions of the Colorado River drainage in Wyoming, Colorado, Utah, Arizona, and New Mexico. Many scientists believe that the Colorado River cutthroat trout currently occupies less than 1% of this historic range.

Within the Little Snake River drainage of southern Carbon County, Wyoming, Colorado River cutthroat trout historically occupied waters of the upper Muddy Creek drainage. Numerous historical accounts of "mountain trout" and "speckled trout" are found in diaries and letters written by explorers as they traveled through the area.

The disappearance of Colorado River cutthroat trout from the upper Muddy Creek basin may have been initiated as early as the 1850s, when these voyagers reported having to ford cutbanks and battle sage along streams. Some suspect that over-trapping of beaver may have resulted in dam failures and destabilization of stream habitats. The resulting channel incision, diminished water tables, increased erosion, and vertical adjustment of the creek channels are conditions which still persist. Introduction of non-native species such as brook trout has also caused decline and degradation of the native Colorado River cutthroat population.

How to Reintroduce a Cutthroat

habitat in need of improvement

The management of Colorado River cutthroat trout in southcentral Wyoming received significant direction in 1994 when the Conservation Plan for Colorado River Cutthroat Trout in the Little Snake River Drainage, Southeastern Wyoming, was signed by the Medicine Bow National Forest, Wyoming Game and Fish Department, and the the Rawlins BLM. The mission of this plan was "To protect and reestablish genetically pure populations of Colorado River cutthroat trout in the Little Snake River drainage for their social, ecological, recreational and aesthetic values." This meant improving stream habitat conditions in the Muddy Creek watershed so that it might once again harbor populations of the trout.

reintroducing cutthroat

In order to accomplish this mission, the Rawlins Field Office teamed up with the Muddy Creek Coordinated Resource Management (CRM) group to improve stream habitat conditions in the upper Muddy Creek watershed. In particular, Littlefield Creek, the site of this first reintroduction, has witnessed dramatic improvements in stream habitat quality thanks to the hard work of Muddy Creek CRM participants from federal, state, and local governments as well as local landowners. Habitat improvement work has been a gradual process and is still proceeding within the upper Muddy Creek watershed.

After preparing the habitat, the next step was to remove non-native fishes that would normally displace or out-compete CRCT. Prior to the removal of these species, two fish barriers were constructed to eliminate the possibility of non-native fishes once again invading streams once the non-natives had been removed. Chemical treatments of Littlefield Creek began in 1999. In 2001, a crew composed of members from the WGFD, USFS, and BLM collected about 500 pure CRCT from Deep Creek on the Medicine Bow National Forest. These fish were then transplanted to Littlefield Creek. This reintroduction marks the first reintroduction of CRCT on BLM lands in southern Wyoming.

This reintroduction has been a great example of how diverse groups can come together in order to accomplish a common goal. With the help of these diverse groups, the Rawlins Field Office will continue working to ensure that there is a place for native species on BLM-administered public lands.

2002 CRCT Habitat Improvement Project

beaver activity at aspen

Beaver in the Littlefield Creek drainage south of Rawlins had their work cut out for them during the fall of 2002l, courtesy of the Bureau of Land Management and Wyoming Game and Fish Department. In September, the BLM airlifted approximately 6,400 pounds of aspen logs to the beaver in hopes they would use the materials for dam building.

The goal of the beaver "feeding" project is to stop a headcut in the creek and improve the riparian and fisheries habitat. The headcut is lowering the stream channel which lowers the water table, making it more difficult for riparian vegetation, such as willows, to become established. Willows and other woody vegetation are needed to shade the water, cooling it to a temperature at which the trout can survive. Trout also like pools in their habitat, and the headcut isn't allowing pools to form. Beaver dams raise the water table, form pools, and flood willow habitat, encouraging its regrowth.

transporting aspen

The agencies first tried the beaver feeding project in 2002 with great results. According to Mike Bower, BLM fisheries biologist, he and co-workers placed some of the aspen logs in the creek so the beaver could get an idea of what was expected of them. "The beaver took apart what we had made, moved the logs a few yards away and redid it. They know better than we do where the dams should be built," said Bower. He added, "They used every ounce we provided last year" (over 12,000 pounds).

habitat upstream of beaver dams

The BLM's fire helicopter was used for the project, and the helicopter's crew was instrumental in the project's success by cutting the aspen and managing the aspen-slinging operation. The aspen source was about 20 miles from the project site, and the helicopter made eight trips ferrying the logs. The Wyoming Game and Fish Department paid for the costs of the helicopter; the BLM provided the labor for the project. The agencies plan to reintroduce another 500 cutthroat to the creek in 2003.