Hooper, 1938 Sarco Cr., #1000 ft., E mi. NE Napa, Napa Co, Calif. June 22, Douglas fir-madrone association - as one goes up-valley to more & more protected, cooler places. This canyon, in which we now are, may mark the southwesternmost limit (north of S.F. Bay) of redwood association. Here about me in this canyon bottom are: redwood, alder, black willow, huckleberry, madrone, poison oak, apple, buckeye (1 or 2), hazelnut, douglas fir, live oak, bay, long-leaved (?) willow, "vine-bush", bracken. The zonation in the canyon bottom I would also say is good transition. Upon the slopes in the chaparral = Upper Sonoran. 9 mi. NW Colistoga, Sonoma Co, Calif. June 23, Drove back to Napa, thence north thru St. Helena & Colistoga, north west on road to Geyserville and Healdsburg... About 46 traps on N-facing slope in alder, live oak, madrone, Douglas fir, redwood, deciduous oak; poison oak near stream (hillside above), for most part! Took 2 L. truei and 16 P. maniculatus. Took 5 L. maniculatus and 3 Microtus on dry, S-facing slope in grass (dry).