Columbia River
               
               
               
               
               
               
               This 2000 km river, roughly 800 km of which wends through Canada, has its source in
                  southeastern 
British Columbia's Columbia Lake. It passes into the United States where it meets the Pacific Ocean
                  at the divide between 
Washington and 
Oregon State.
Spanish explorers had named it Rio de San Roque in 1775, and it was called Oregon
                  River by 
Jonathan Carver in 1766; it was not until 1792 that Boston trader 
Captain Robert Gray named it after his ship.
                  
David Thompson, then of the North West Company, explored the westward Columbia in 1811 to find American
                  traders already present in 
Fort Astoria, on the south side of the Columbia's delta.
                  
As several early despatches show, this river served as a natural border between British
                  and US interests until, after much tension in 
Oregon Territory, the Oregon Treaty of 1846 settled an enforceable borderline north of the Columbia
                  to the 49th parallel, which is now the Canada-US border.