The Ashley National Forest has issued a temporary closure for North Fork Sheep Creek through September 2, 2026, to facilitate the second scheduled rotenone treatment for native cutthroat trout restoration. This phase of the conservation project follows an initial treatment in the Fall Creek drainage that took place between August 3 and August 6, 2026.
Safety and Access Restrictions
The closure, which began on August 19, 2026, prohibits public access within 20 feet of North Fork Sheep Creek. The U.S. Forest Service stated the restriction is necessary to allow ground crews to work safely in and around the treated waters. While the area within 20 feet of the creek is closed, all hiking trails and other access points in the area will remain open to public use.
According to the Utah Division of Wildlife Resources, the North Fork Sheep Creek treatment is scheduled for August 19 and August 26, 2026. This marks the first year of treatment for the North Fork of Sheep Creek, whereas the Fall Creek drainage treatment marks the second year of efforts in that area. The Forest Service noted that the closure is intended to protect public health and safety during the application of rotenone.
Restoration Methods and Salvage
Rotenone, a natural respiratory toxin derived from the roots of a tropical bean family plant, is being used to remove non-native species including brook trout, non-native cutthroat trout, and rainbow trout. The Utah Division of Wildlife Resources noted that while rotenone is a respiratory toxin to fish, it is not dangerous to people, pets, or other wildlife when used in the extremely low quantities required for stream and lake treatments.
Biologists will conduct fish salvage efforts prior to the treatment, particularly in North Fork Sheep Creek, which currently holds a genetically pure population of Colorado River cutthroat trout. All size classes of cutthroat trout that can be removed before the treatment will be held onsite and released back into the creek once the water has oxidized to help repopulate the stream.
Long-term Conservation Goals
The restoration efforts aim to combat dramatic declines in native cutthroat trout populations caused by habitat loss, competition from non-native trout, and spawning with non-native species. Biologists warned that without intervention, brook trout populations could completely replace cutthroat trout in these areas in less than 20 years.
Natalie Boren, the Utah Division of Wildlife Resources Northeastern Region Aquatics Manager, stated that the agency has made significant progress on Colorado River cutthroat trout restoration in northeastern Utah over the last 20 years. Boren noted that building resilient populations across the landscape will help ensure the species persists into the future. This work is intended to prevent the species from being listed under the Endangered Species Act.
Regional Impact and Angling
The scope of the restoration project is part of a larger effort to treat the upper portions of streams connected to the Sheep Creek canal. In the Fall Creek drainage, the success of this year's treatment will determine whether Colorado River cutthroat trout are stocked into Phinney Lake and Anderson Lake in 2027.
Carsen Hinkhouse, the Utah Division of Wildlife Resources Regional Sportfish Biologist, said the Uinta Mountains host over 1,000 lakes and hundreds of miles of stream, but efforts are targeted at restoring the Colorado River cutthroat trout in a specific handful of these waters. These efforts are also expected to meet angling preferences, as recent surveys show an increased preference for cutthroat trout among anglers.
Compliance and Contact Information
Violations of the Forest Service order regarding the North Fork Sheep Creek closure are punishable as a Class B misdemeanor. Individuals may face a fine of up to $5,000, while organizations may face fines up to $10,000. Convictions may also result in imprisonment for up to six months.
For more information regarding the order, the public can contact the Flaming Gorge Ranger District at 435-784-3445 or the Ashley National Forest Supervisor’s Office at 435-789-1181. The Utah Division of Wildlife Resources Vernal office can be reached at 435-781-9453 for questions regarding the waterbody treatments.
