Cutthroat Trout - The cutthroat trout is a fish species of the family Salmonidae native to cold-water tributaries of the Pacific Ocean, Rocky Mountains, and Great Basin in North America, and is the state fish of Wyoming. As a member of the genus Oncorhynchus, it is one of the Pacific trout, a group that includes the widely distributed rainbow trout. Throughout their native and introduced ranges, cutthroat trout vary widely in size, coloration and habitat selection. Their coloration can range from golden to gray to green on the back.Depending on subspecies, strain and habitat, most have distinctive red, pink, or orange linear marks along the underside of their mandibles in the lower folds of the gill plates. These markings are responsible for the common name "cutthroat", first given to the trout by outdoor writer Charles Hallock in an 1884 article in The American Angler. These markings are not unique to the species. Some coastal rainbow trout (Oncorhynchus mykiss irideus) and Columbia River redband trout (O. m. gairdneri) populations also display reddish or pink throat markings. Cutthroats comprise at least 14 separate subspecies.