The Utah Division of Wildlife Resources is launching a series of waterbody treatments in the High Uintas to restore native Colorado River cutthroat trout populations. The initiative, conducted in coordination with the U.S. Department of Agriculture Forest Service, aims to remove non-native fish from key drainages to ensure the survival of the native species.
Restoration Strategies and Timelines
The 2026 restoration efforts focus on two specific areas within the High Uintas. Biologists will treat the Fall Creek drainage on the south slope from Aug. 3-6, with the area expected to reopen to the public on Aug. 8. The second phase will target the North Fork Sheep Creek on the north slope on Aug. 19 and Aug. 26, according to a July 28 announcement from the Division of Wildlife Resources.
This year marks the second year of treatment for the Fall Creek drainage, while the North Fork of Sheep Creek will undergo its first treatment. These efforts are part of a larger, long-term strategy to combat the decline of native trout caused by habitat loss, competition, and spawning with non-native species. Biologists warned that without such intervention, brook trout populations could completely replace native cutthroat trout in these areas in less than 20 years.
The Role of Rotenone
To facilitate these treatments, biologists will use rotenone, a natural substance derived from the roots of tropical bean family plants. While rotenone acts as a respiratory toxin to fish, the Division of Wildlife Resources noted that the extremely low quantities used in streams and lakes are not dangerous to humans, pets, or other wildlife.
Because the North Fork of Sheep Creek currently holds a genetically pure population of Colorado River cutthroat trout, biologists will conduct fish salvage efforts prior to the treatment. All size classes of cutthroat trout that can be safely removed will be held onsite and released back into the creek once the water has oxidized, ensuring the population can be repopulated. The treatments are designed to remove brook trout, non-native cutthroat trout, and rainbow trout from the target areas.
Logistics in the Wilderness
The remote nature of the High Uintas necessitates complex logistics. For the Fall Creek project, which involves treating seven miles of stream and two high mountain lakes, the Division of Wildlife Resources is utilizing horse outfitters to transport equipment and personnel. The project requires a team of 16 biologists and seasonal staff to trek 13 to 16 miles into the wilderness from the Stillwater Reservoir Trailhead.
According to the Utah Watershed Restoration Initiative, the Division of Wildlife Resources is working to eradicate brook trout from the Fall Creek drainage to prepare for the reintroduction of native trout. This specific project is located approximately 60 miles north of Duchesne in northern Duchesne County. The use of outfitters to haul gear—including rotenone, sprayers, and camping equipment—is considered essential for the success of the mission in such rugged terrain.
Long-Term Conservation Goals
The Division of Wildlife Resources emphasized that the success of these treatments is vital for the long-term resilience of the species. Natalie Boren, the Division's Northeastern Region Aquatics Manager, stated that making significant progress on restoration over the past 20 years is key to building resilient populations that will persist into the future.
If the Fall Creek treatments are deemed successful, the Division plans to stock Colorado River cutthroat trout into both Phinney Lake and Anderson Lake in 2027. Regional Sportfish Biologist Carsen Hinkhouse noted that while the effort targets a handful of waters, these actions ensure native trout remain on the landscape while providing diverse angling opportunities. Currently, Colorado River cutthroat trout occupy only 11% of their historical range.
Impact on Public Access
The restoration efforts also align with angler preferences. Recent surveys have indicated an increased preference for cutthroat trout among the public. While the treatments temporarily prohibit public entry into the treated waters and prevent the use of those waters for drinking, the Ashley National Forest will keep all hiking trails and other access points open to the public.
The Division of Wildlife Resources continues to manage a wide variety of fishing opportunities across Utah. For those seeking different species, the Division's Fish Utah interactive map provides information on where to catch various fish. The Division also manages the Blue Ribbon Fisheries program, which identifies high-quality waters that provide excellent fishing experiences and economic benefits to local communities.
Fishery Management Context
The Blue Ribbon Fisheries program, which oversees the designation of high-quality trout waters, has historically supported significant habitat improvements. Since the program's inception, over $4.2 million has been allocated to more than 210 projects, contributing to a larger $46.5 million investment in improving angler access and fish habitat across the state.
As the Division of Wildlife Resources continues its work in the Uintas, the goal remains to maintain abundant angling opportunities for multiple species, including both brook trout and cutthroat trout, while protecting the ecological integrity of Utah's watersheds.
