Nooper, 1936 Smoke Cr., 3900 ft., 7 mi. & Calif. line Washoe Co., Nev. July 7, had not been used for several months. Two rat traps set in the "kitchen" near our food boxes yielded 2 Neotoma cinerea. Bats were noted last evening. 1 Eptesicus fuscus was shot. July 8, Set out 50 mouse traps, 10 paces apart, on fine sandy areas and on coarse sand areas. about ½ mi. N of camp. Sarcobatus was the most conspicuous plant in the area trapped. Found in traps this morning: 1 Ammospermophilus, 3 Dipodomys microps, 2 D. ordii, 3 Microdipodops, 3 Peromyscus maniculatus, 1 Reithrodonmys megalois, 1 Perognathus parvus. Set 2 rat traps in the ranch house where we camp. Caught this morning 1 Neotoma cinerea. July 9, Took 1 more Neotoma cinerea from 1 of 2 rat traps set in this old cabin. These rats are exceedingly abundant here. They inhabit this house, outlying outhouses, old cottonwood stumps, rock piles, and piles of debris (which, for the most part, have been formed during high water periods of the creek and were not, probably, built by the rats). At night they can be heard climbing about in trees and running about on the dry.