Northwestern Forested Mountains
The Northwestern Forested Mountains is a Level I ecoregion of North America designated by the Commission for Environmental Cooperation (CEC) in its North American Environmental Atlas. Hydrology Most of the water in this ecoregion is fresh water and contained in rivers, lakes, and groundwater. Washington, Oregon, and Idaho are mainly drained by the Columbia River, its tributaries, and other streams that flow to the Pacific Ocean. The Columbia River Basin is the fourth largest watershed in North America. According to a 2004 GIS inventory by the Environmental Protection Agency, there are approximately 10,535 lakes and reservoirs in the Pacific Northwest. The largest lakes in the Pacific Northwest include Lake Washington, Lake Roosevelt, Lake Chelan, Upper Klamath Lake, Lake Pend Oreille, Priest Lake, and Lake Coeur d'Alene. In British Columbia, the Fraser River watershed covers one-fourth of the land and extends from Mount Robson to the Georgia Strait and Gulf Islands. This basin is the fifth largest drainage basin in Canada and contains thirteen main sub-watersheds, each consisting of small rivers, streams, creeks, marshes, bogs, and swamps. The largest lake in British Columbia is Williston Lake which covers . Alaska contains abundant natural resources which include ground and surface water. The