Osoyoos Lake is a lake located in British Columbia and Washington. Osoyoos is derived from the word suius meaning "narrowing of the waters" in the local Okanagan language (Syilx'tsn).Located on the lakeshore are the towns of Osoyoos, British Columbia and Oroville, Washington. The lake's maximum elevation is 912.78 ft (278.22 m), while its minimum elevation is 909.46 ft (277.20 m). The 62-year average discharge into the Okanogan River at Oroville is 683 cu ft/s (19.3 m3/s).