The Yellowstone cutthroat trout is visually distinguished from other trout species by its two prominent red slashes on the lower jaw, and from other cutthroat trout subspecies by its medium-large, black spots that tend to be concentrated posteriorly, and its drab brownish, yellowish, or silvery coloration, with brighter colors generally absent even in mature fish. Tiny teeth are usually present on the floor of the mouth behind the tongue. Red on the side of the head and gill cover becomes intense in the breeding male.