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.
Pend Oreille River
The Pend Oreille River ( ) is a tributary of the Columbia River, approximately long, in northern Idaho and northeastern Washington in the United States, as well as southeastern British Columbia in Canada. In its passage through British Columbia its name is spelled Pend-d'Oreille River. It drains a scenic area of the Rocky Mountains along the U.S.-Canada border on the east side of the Columbia. The river is sometimes defined as the lower part of the Clark Fork, which rises in western Montana. The river drains an area of , mostly through the Clark Fork and its tributaries in western Montana and including a portion of the Flathead River in southeastern British Columbia. The full drainage basin of the river and its tributaries accounts for 43% of the entire Columbia River Basin above the confluence with the Columbia. The total area of the Pend Oreille basin is just under 10% of the entire Columbia Basin. Box Canyon Dam is currently underway on a multimillion-dollar project for a fish ladder.