The rugged mountains of the Northwest consist of the Coast Range, which is nearer the coast, and the Cascade Range. In northern Washington, the Cascade Range is called the North Cascades. In British Columbia, it is called the Canadian Cascades. The many rivers of the Northwest result from its wet climate - the mountains trap wet Pacific air, leaving little rain for inland states like Idaho. The rivers once supported large salmon runs, but large power dams have been built on many rivers.