764 Peromyscus maniculatus gambelli (1) Mad R. Fork, 2700 ft., above Ruth, Trinity Co., Calif. May 20, 1933 Most numerous; are taken in traps set along stream, on logs, on bank and on flat under bushes. Immatures of its year are already out. May 26, 1933 Generally found in fir, spruce, willows, stream side etc. May 29, 1933 Eight specimens caught at 5500 ft. in damp timber and dry rock-chinquapin associations. The habitat of this mouse seems to be along watercourses & rocks from within 2 valley to top of mountain. It is not found in the dry deep timber where only truei has been caught. Habitat in places unlike - might with that of P. boylei.