Hooper, 1938 Berkeley, Alameda Co., Calif. June 13, I also set 50 traps among poison oak, California bay, Santhus, and yellow pine; substrat mostly rocky (rocks ranging from 6 in. diameter to large boulders) -- like a talus slope in the Sierra Nevada, but rocks rounded, water-worn. Many of the rocks covered with moss, now mostly dry, and area giving evidence of considerable down-work of water in wet season. Took from traps: 7 L. trui + 2 L. californicus. We estimated that there were 135 yellow pines (mostly large trees of about 3 ft. diam.) in the area of about 20 acres. They are not in pure thick stands as a rule but mixed with P. coulteri and, less often, with P. sabina. Vegetation bordering or among them: Calif. bay, Santhus, manzanita, madrone, adenostima, Coulter pine, digger pine. Some of the area seems excellent for chipmunk subsistence and possibly gray squirrel, but none was seen. After picking up traps drove back to Berkeley, arriving here at about 11:30 A.M.