Vernal — The Utah Division of Wildlife Resources (DWR) is gearing up for the Colorado River Cutthroat Trout Restoration Project for the Middle Fork of Sheep Creek in the Uinta Mountains. The project is scheduled for September 2012.

Treating the Middle Fork of Sheep Creek is the first step in bringing native Colorado River cutthroat trout back to the creek.

Photo by Ron Stewart

"The on-the-ground work will take place in September to avoid the busy summer visitor's season," said Trina Hedrick, regional aquatics manager for the DWR. "We just unloaded a shipment of rotenone, and we've got a lot of things to do to get ready."

The project has been on the books for a long time. "We've been waiting for the right conditions to start, which included getting adequate funding, personnel and fish in the Utah hatchery system for restocking," Hedrick stated.

The ultimate goal is to reestablish viable populations of Colorado River cutthroat trout (CRCT), the only trout native to the Uinta Mountains. A brood population for North Slope lakes is being developed, but there will not be enough CRCT to restock the entire area after the treatment project. Tiger trout, a sterile hybrid from brown and brook trout, will supplement the restocking efforts until there are enough CRCT to replace them.

"The treatment area covers the upper reaches of the Sheep Creek drainage, which includes roughly 8.7 miles of streams and nine lakes, the best known being Spirit Lake," Hedrick said. "Other lakes include Jessen, Tamarack, Summit, Gail, Judy, Columbine, Lost and Hidden. All but Summit Lake can support fish populations."

All of the nonnative fish, including brook, rainbow, Yellowstone cutthroat and hybridized cutthroat trout, will be removed. A barrier, constructed in 2004, will keep the nonnative fish from reestablishing themselves in the area that will be treated.

"After we determine that we've had a successful treatment, likely next summer, fish will be restocked," Hedrick said. "The number of eggs we can collect varies year by year. If there aren't enough North Slope CRCT in the system, we may elect to restock with sterile tiger trout to reestablish a fishery until enough CRCT are available.

"To provide an additional fishing opportunity, Spirit Lake will likely be stocked with CRCT and tiger trout. Because the tigers cannot breed, we can control their numbers. Also, the tiger trout will not hybridize with the CRCT."

This effort to restore the native CRCT to its natural waters will also help prevent the fish from being listed as an endangered species.

"Colorado River cutthroat trout are the only trout species native to the Colorado River drainage," said Garn Birchell, DWR biologist and project leader. "Historically, they were distributed in all suitable waters in the Green/Colorado River drainage. Currently, however, CRCT exist only within fragmented components of their historic range.

"Their decline is attributed to loss of habitat, interspecific competition from non-native fishes—generally brook or brown trout—and loss of genetic purity from hybridization with rainbow and other subspecies of cutthroat trout.

"In the early 2000s, CRCT were petitioned for listing as a threatened species under the Endangered Species Act (ESA)," Birchell said. "In April 2004, the U.S. Fish and Wildlife Service (USFWS) ruled that listing CRCT for ESA protection was not warranted. Listing was denied again after a second appeal a few years later. One reason cited by the USFWS for not listing CRCT was that a significant conservation effort had already been implemented by the states of Utah, Colorado and Wyoming."

A Conservation Agreement for CRCT restoration was developed for the state of Utah in 1997. The Tri-State Conservation Agreement outlining plans to restore CRCT into portions of their historic range was signed in 1999 and renewed in 2006.

"Tributaries of the Green River comprise a significant portion of CRCT historic range," Birchell said. "Our region is heavily involved because restoration efforts focus on three subunits—the North Slope Uinta Mountains, South Slope Uinta Mountains and North Tavaputs Plateau. The Sheep Creek drainage in the North Slope subunit is a critical area identified for CRCT restoration."

Project specifics

• Rotenone will be used to treat all lakes and streams
• The rotenone will be applied over a two- to three-day period in September
• 8.7 miles of stream and nine lakes to be treated
• A crew of roughly 60 people will be involved in the treatment project
• Drip stations and backpack sprayers will be used to treat the streams while motorized boats and rafts (delivered by helicopter to isolated lakes) will be used to treat the lakes
• Potassium permanganate will be applied to neutralize rotenone- treated waters below the barrier
• The project will begin after the Labor Day weekend when visitation to the area is reduced and hopefully prior to snowfall
• Because helicopters will be used to transport equipment and gear into remote areas, there will be some local area closures to ensure safety
• Connected waters will require two treatments (2012, 2013)
• After the first treatment, when the rotenone is deemed to be inactive, Spirit Lake will be restocked with tiger trout or sterile rainbow trout to provide a recreational fishery between treatments
• If the first treatment is successful at Gail, Judy and Columbine lakes, then fingerling tiger trout will be stocked into these lakes in July 2013
  
  Note: The DWR anticipates that the lakes will need only one treatment. The lakes have no outlet flow, and they're isolated from the tributaries
• After a successful second treatment (2013), lakes and tributaries will be restocked with Colorado River cutthroat trout or tiger trout during the fall (2013) or the following summer (2014)
• The tributaries will be managed as wild trout fisheries
• The DWR anticipates regular stocking will not be necessary after CRCT are established in the tributaries
• Lakes will be managed as wild or stocked depending on conditions and use