Nonnative Brook Trout Discovered in Soda Butte Creek in Yellowstone National Park

Yellowstone National Park sign at the North Entrance; Jim Peaco; October 1992

Yellowstone National Park, in coordination with Montana Fish, Wildlife & Parks and Custer Gallatin National Forest, will resume the Soda Butte Creek Native Fish Restoration Project near the Northeast Entrance Aug. 14-18 to remove newly discovered nonnative brook trout. The fish restoration project concluded in 2016 after nonnative brook trout were completely removed from the waterway due to successful treatments. If not addressed this month, brook trout will quickly displace native Yellowstone cutthroat trout and eventually invade the entire Lamar River watershed, threatening the largest remaining riverine population of Yellowstone cutthroat trout in existence.

Aug. 14-18, Soda Butte Creek will be closed to the public from the park boundary at the Northeast Entrance to Ice Box Canyon (9.6 miles) while biologists remove brook trout by applying an EPA-approved piscicide (rotenone). Warm Creek and Soda Butte Creek picnic areas will also be closed for project staging. View a map for details.  

Cutthroat trout will be moved out of the treatment area this week by electroshocking. The salvaged cutthroat trout will be held in the Soda Butte Creek watershed in upper untreated tributaries.  

Cutthroat trout will be released back into Soda Butte Creek once fisheries staff complete the treatment.  

Cutthroat trout are the only trout species native to the park. They are the most ecologically important fish of the Greater Yellowstone Ecosystem and are highly regarded by anglers. Genetically pure Yellowstone cutthroat trout populations have declined throughout their natural range in the Intermountain West, succumbing to competition with and predation by nonnative fish species, a loss of genetic integrity through hybridization, habitat degradation and predation.Learn more about the Soda Butte fish restoration and ongoing preservation efforts at Native Fish Conservation Program.