Tuesday September 1, 2026
Wired2Fish —
Yellowstone National Park will temporarily close Buffalo Creek, a tributary of Slough Creek in the park’s northern reaches, from Aug. 31 through Sept. 6 while fisheries biologists treat the stream to remove invasive rainbow trout. The project will use rotenone, a piscicide or fish poison. Buffalo Creek is closed from the northern park boundary downstream to its confluence with Slough Creek. Park officials say the treatment will not affect the potability of water at Slough Creek Campground, and the creek is scheduled to reopen to the public Sept. 7.
The project targets a population of rainbow trout (Oncorhynchus mykiss) that serves as a source of invasive fish moving into Slough Creek, Soda Butte Creek, and the Lamar River, where they compete and hybridize with native Yellowstone cutthroat trout (Oncorhynchus virginialis bouvieri). Removing the source population in Buffalo Creek is considered an important step in protecting the long-term persistence and genetic integrity of Yellowstone cutthroat in the Lamar River watershed.
Although Yellowstone cutthroat rarely occur in Buffalo Creek, biologists will electrofish the stream before treatment and relocate any native cutthroat they find outside the treatment area. The effort is part of Yellowstone’s broader native-fish conservation program, aimed at addressing the pressures that non-native fish, hybridization, and habitat degradation all place on the park’s native trout.