The Yellowstone Cutthroat Trout (Oncorhynchus clarkii bouvieri) is a subspecies of cutthroat trout native to the Yellowstone and Upper Snake River drainages of Montana, Idaho, Wyoming, and small areas of Utah and Nevada. This freshwater fish is recognised by its distinctive red or orange slash marks beneath the lower jaw. It inhabits clear, cold streams, rivers, and lakes, feeding primarily on aquatic insects and smaller fish. Conservation efforts are ongoing to address threats from habitat degradation, competition with non-native species, and hybridisation.