The largest cutthroat trout subspecies is the Lahontan cutthroat trout . Inland grizzlies may eat fish too, most notably in Yellowstone grizzlies eating Yellowstone cutthroat trout. Brook trout have an advantage over cutthroat trout because they spawn in fall. The formerly abundant kokanee were extirpated, and native bull and westslope cutthroat trout are imperiled. Four trout species inhabit park waters&colon; rainbow, brook, cutthroat, and German brown trout. This type specimen was most likely the coastal cutthroat trout subspecies . Some populations of the coastal cutthroat trout are semi-anadromous. A population of Yellowstone cutthroat trout purportedly has been established in Lake Huron. This seriously damaged the stream's ecology and impacted the native Yellowstone cutthroat trout population. Rio Grande cutthroat have the distinction of being the southern most subspecies of cutthroat trout. The Greenback cutthroat trout was originally thought extinct in 1937. Sea-run forms of coastal cutthroat trout average . It is one of three subspecies of cutthroat trout that are listed as federally threatened. Numerous trout species are found, among them rainbow, golden, and cutthroat. Today only native cutthroat and non-native Lake trout exist in the lake.