GSA Abstracts with Programs, vol. 27, no. 3, p. 57.
THE 1994 EXCAVATION OF A QUATERNARY VERTEBRATE FOSSIL DEPOSIT FROM BUMPER CAVE, PRINCE OF WALES ISLAND, ALASKA.

Timothy H. Heaton
Department of Earth Sciences
University of South Dakota
Vermillion, SD 57069
David C. Love
Auk Bay Laboratory
Nat. Marine Fisheries Service
Auk Bay, AK 99821.

Bumper cave is located in SEČ, Sec. 22, T65S, R77E on the Petersburg A-5 NE quadrangle at an elevation of 1733 feet. This is a subalpine, forested, metamorphic karst area five miles east of Mt. Calder on the northern end of Prince of Wales Island, southeast Alaska. The cave runs southwest from the entrance about 65 feet, has an average passage width of six feet, and has an average height of three feet. The floor is flat to gently sloping and varies from rock rubble near the entrance to fine mud at the back. The cave was discovered and mapped in 1993 by Kevin Allred and David Love, who found an extensive bone deposit along the entire length of the passage.

We spent ten days mapping and excavating the deposit in July of 1994. Remains of at least nine bears were recovered, all probably grizzly bears (Ursus arctos, not a current inhabitant of the island). A nearly complete skeleton of a female was found in the back of the cave, part of which had fallen down a sump. Parts of two juveniles were found nearby. Remains closer to the entrance were more disarticulated, less complete, and more weathered. Among the remains in the entrance room was the lower molar of an exceptionally large bear, probably a male Ursus arctos.

In spite of the large collection of bear remains, the diversity of the Bumper Cave fauna is extremely low. The screen washing of nearly a ton of cave sediment produced remains of only two genera: Ursus (bears) and Microtus (voles). But the site has three strikes against it in terms of diversity: 1) it's at a high latitude, 2) it's on an island, and 3) it's at a high elevation on the island


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