The Nez Perce territory at the time of Lewis and Clark (1804–1806) was approximately 17000000 acres and covered parts of present-day Washington, Oregon, Montana, and Idaho, in an area surrounding the Snake (Weyikespe), Grande Ronde River, Salmon (Naco’x kuus) ("Chinook salmon Water") and the Clearwater (Koos-Kai-Kai) ("Clear Water") rivers.