نهر كولومبيا (Upper Chinook: Wimahl or Wimal; Sahaptin: Nch'i-Wàna or Nchi wana; Sinixt dialect swah'netk'qhu) is the largest river in the Pacific Northwest region of North America. The river forms in the Rocky Mountains of British Columbia, Canada.It flows northwest and then south into the U.S. state of Washington, then turns west to form most of the border between Washington ...