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.
Nutrient cycling in the Columbia River Basin
Beginning in the 1930s with the construction of the Bonneville and Grand Coulee dams, the Columbia River has experienced significant modification to its flow. Today, the US Army Corps of Engineers recognize over 250 reservoirs, 150 hydroelectric projects, and 18 mainstem dams on the Columbia and its main tributary, the Snake River. Dams have been shown to directly impact nutrient cycling within the Columbia river basin through the formation of reservoirs which dramatically alter river hydrology and discharge rates and as a result constitute a major anthroprogenic impact on nutrient cycling in the river. Due to its size and the large number of dams within the basin, the Columbia River basin is often used as representative case study on how dams an impact nutrient cycling of watersheds in general. Notably, dam construction in the Columbia River Basin has impacted relative nutrient ratios, methane production, and salmon migration.