Studies of small mammal occurrence at high altitudes in the Sierra Nevada are uncommon, so the opportunity for even a short examination was welcomed. The period of August 17–26, 1954, was spent at lower Graveyard Lake, 9,900 feet, Sierra National Forest, Fresno County, California. This locality is approximately eight miles from the nearest jeep road. A northeast slope of approximately 45 degrees, leveling off near the top, was arbitrarily picked for the study. Nothing was known or was learned of the comparative characteristics of adjacent areas of other exposures and degrees of slope. The soil was granitic in its entirety and was gravelly in nature, except in the meadows where it was loamy in texture and contained some humus. As illustrated (Fig. 1), a low form of willow ( Salix orestera ) was common over the center of the plot, with meadow bordered by willow at the top. The common herbaceous species, in the meadow and interspersed in the willow, was Carex exserta . The sides and most of the bottom of the plot, as illustrated, were open, rocky, and almost bare of herbaceous vegetation. Small lodgepole pine ( Pinus contorta ), an occasional white-bark pine ( Pinus albicaulis ), and …