Columbia River
The Columbia drains an area of about . Its drainage basin covers nearly all of Idaho, large portions of British Columbia, Oregon, and Washington, ultimately all of Montana west of the Continental Divide, and small portions of Wyoming, Utah, and Nevada; the total area is similar to the size of France. Roughly of the river's length and 85 percent of its drainage basin are in the US. The Columbia is the twelfth-longest river and has the sixth-largest drainage basin in the United States. In Canada, where the Columbia flows for and drains , the river ranks 23rd in length, and the Canadian part of its basin ranks 13th in size among Canadian basins. 
The Columbia shares its name with nearby places, such as British Columbia, as well as with landforms and bodies of water.
Western Canada
The Canadian Rockies are part of a major continental divide that extends north and south through western North America and western South America. The continental divide also defines much of the border between Alberta and British Columbia. The Columbia and the Fraser Rivers have their headwaters in the Canadian Rockies and are the second- and third-largest rivers, respectively, to drain to the west coast of North America. To the west of their headwaters, across the Rocky Mountain Trench, is a second belt of mountains, the Columbia Mountains, comprising the Selkirk, Purcell, Monashee and Cariboo Mountains sub-ranges.