Activity of Park Beaver
By O. L. Wallis, Ranger-Naturalist

Beaver activity in Crater Lake National Park at present is at a low ebb. A survey of the old workings of the American beaver (Castor canadensis pacificus), in the Copeland Creek region reveals that there has not been any renewal for many years. Several of the dams observed in 1931 by the park naturalist, (Nature Notes Volume 4 No. 1, July 1931) still exist and are strong enough to retain a great quantity of water.

Observations in the Annie Creek basin near the South Entrance show that beaver have been active here to a limited extent. Cuttings estimated from the weathering to be no older than four months occur in the quaking aspens and the poplars along the stream bed. Older cuttings were seen on white fir, aspen, and poplar trees. One tree, 15 inches in diameter, remains standing although almost completely cut through.

Wildlife expert Robert S. Evans in his 1934 "Survey of Animal Life of Crater Lake National Park" states: "Since last year when an estimated number of 12 was reported for beaver living along the streams of the west slope, fresh beaver work has been found along Annie Creek in the southeast corner of the park;" the 1934 estimate was 18, but that exceeds the numbers which exist in the park today.

The beaver migration from the areas on Copeland Creek and Annie Creek probably resulted from one or both of two main causes: lack of sufficient food to support a colony and freezing of the water too deeply to permit winter activity.