The Similkameen River runs through southern British Columbia, Canada, eventually discharging into the Okanogan River near Oroville, Washington, in the United States. The river is about 197 km (122 mi) long, with a drainage basin area of 7,600 km2 (2,900 sq mi). The river is said to be named for an indigenous people called <Similkameigh>, meaning "treacherous waters".