Starting next week Yellowstone National Park staff will begin chemically treating the upper Gibbon River, continuing a project to remove nonnative fish in central Yellowstone.
Biologists will add the fish toxin rotenone - a chemical that comes from roots of tropical plants - to the river to remove nonnative rainbow and brook trout. They’ll add another chemical to the water at the bottom of the treatment area to remove the effects of the toxin and prevent further impacts downstream.
During the treatment, from August 20 to the 26, the Wolf Lake Trail and Virginia Cascades Drive will be closed to the public.
These treatments will be repeated in 2019, and again in 2020 if necessary. Reintroduction of native westslope cutthroat trout and fluvial arctic grayling will start in 2021.
The park has restored these species in the East Fork of Specimen Creek, Goose Lake, and Grayling Creek.