The Columbia River undergoes drainage.
The Columbia River (Upper Chinook: Wimahl or Wimal; Sahaptin: Nchi-Wna or Nchi wana; Sinixt dialect swah'netk'qhu) is a major river which flows through southern British Columbia, central Washington and forms a portion of the Washington - Oregon boundary before emptying into the Pacific Ocean
== Watershed ==Most of the Columbia's drainage basin (which, at 258,000 square miles or 670,000 square kilometres, is about the size of France) lies roughly between the Rocky Mountains on the east and the Cascade Mountains on the west

