R. Pearson 1950 the South fork of the America River. It is on forested land owned by the Portland Cement Co., but we got permission to stay from the two men who are working here now at demolishing the old buildings. They showed us some cracks in the building where bats were roosting and we extracted 3 Myotis yumanai. There were also Ictidomys in the cracks. Set out 42 traps -- some along a little stream on the north- sloping hill by camp and some in more open country under isolated bruster and in holes along the road. He set one steel trap in a culvert. April 16, 1950 My 42 traps produced 11 Perognathus truei and one hermit thrush. Also caught a wood rat in the culvert. He skinned in the morning (Mary had a Microtus but other than that there were only more Perognathus truei). Set out another line along the river, many in moss-covered rocks on the hillside lining the river. 50 t traps. After lunch we drove to the hill on the other side of the river, where Mainella & Mary set out some traps in the low chaparral that covers that slope. Subsequently looked for bats in the hollow cement support at the ends of an obsolete railroad bridge. Found one room with many droppings, likely a night-roosting place. More skinning after supper -- one Perognathus maniculatus which was caught in the wood pile at the head of our sleeping bags, and otherwise just more Perognathus (truei?). Checked on night