Sockeye Salmon (O. Nerka) historically occupied the four natural lakes in the Yakima River basin (Keechelus, Kachess, Cle Elum, and Bumping Lakes) and their upstream tributaries, as did resident fish including Bull Trout (Salvelinus Confluentus). Cle Elum Lake has the most potential but is the most difficult to pass. If fish passage can be achieved at Cle Elum Dam than all the other reservoirs should fall in to place.