Yellowstone National Park is preparing to temporarily close part of Buffalo Creek as part of a targeted effort to remove invasive rainbow trout. The northern section of the creek will be closed to visitors from August 31 through September 7 while biologists treat the waterway with rotenone, an EPA-approved piscicide, according to NBC Montana. The park stated that the operation is intended to protect Yellowstone cutthroat trout, the only trout species native to the park, from competition and hybridization with the invasive rainbow trout. The project is part of a broader native fish conservation programme aimed at maintaining the ecological health of the Lamar River basin.