The Cutthroat Trout in St. Mary's River are a species of the Salmonoid family. They are native to the west slope of the Rocky Mountains. Cutthroat stay mainly in fast moving fresh water throughout their lives and are non-migratory stream or riverine habitants. The name refers to the distinctive red slash of colour on the underside of the lower jaw. They are an important food source for the Ktunaxa Nation.