Columbia River drainage basin

The Columbia River drainage basin is the drainage basin of the Columbia River in the Pacific Northwest region of North America. It covers 668,000 km² or 258,000 sq mi.^[1] In common usage, the term often refers to a smaller area, generally the portion of the drainage basin that lies within eastern Washington.^[1]

Usage of the term "Columbia Basin" in British Columbia generally refers only to the immediate basins of the Columbia and Kootenay Rivers and excludes that of the Okanagan, Kettle and Similkameen Rivers.

^ ^a ^b Floyd, Ben; et al. (1998). "Glossary". Hanford Reach Protection and Management Program Interim Action Plan. Prosser, Washington: Benton County Planning Department. Archived from the original on March 22, 2005.