I do not know if there are no natives on the Cow, but here is one possible explanation of how a native showed up on that river. It may have not been a native. If that river system uses those new machines to clip the adipose fins, rather then manually having a person clip them by hand, it clips alot of them short and they actually grow back making you think it was a wild steelhead. At least that was how it was explained to me by a gentleman I met on the river who worked for the Oregon hatchery system for eight years.