Beavers live in streams and lakes of Washington under diverse climatic conditions. They are perhaps most abundant in the western Washington lowlands where there are numerous watercourses. In the Cascade Mountains they are found well up into the Canadian Life-zone, where the streams are swift and clear with stony bottoms. The highest altitudinal record known to us is Reflection Lake, Mt. Rainier, 4,861 feet ([Brockman], 1939: 71). Farther east, in the timbered regions of the eastern Cascades and in northeastern Washington, beavers live in deeper, more sluggish streams. Abundant beaver signs were noted at the junction of the Snake and Columbia rivers where the animals were occupying one of the hottest, most desertlike portions of the state. They are found in Moses Lake, in the center of the arid Columbian Plateau. Beavers once occurred in the San Juan Islands and have recently been reintroduced there.
Fig. 100. Beaver (Castor canadensis): lodge and beaver pond, Elbe, Washington, August 24, 1926. (T. H. [Scheffer] photo.)
The part the beaver played in man's exploration of the state of Washington is a story in itself. The establishment of Fort Vancouver and Fort Spokane and other settlements was principally due to the trade in beaver pelts. These forts served as headquarters for Douglas, [Suckley], [Townsend], Nuttall and other early naturalists who contributed so greatly to the knowledge of the mammalian fauna of the western United States.
Fig. 101. Cottonwood pole carved by beaver, Lake Wenatchee, Washington, May 13, 1938. (Fish and Wildlife Service photo by Victor B. [Scheffer], No. 33.)