Latfield -1934 Colorado R., 1/2 mi. N Calif.-Nev. Monument, 560 ft., Clark Co., Nev. January 26, 1934 Drove north of Needles on river road. Spent morning looking for campsite. Saw two marsh hawks over sloughs on way north. At present camp have seen vermilion flycatcher, black phoebe, and heard horned owl. We are camped on mesa directly above a swamp about 2-3 miles north of the state line. Set out 75 traps on mesa. There are numerous burrow entrances present here. January 27, 1934 Caught in traps- 10 Dipodomys merriami 1 Perognathus formosus Spent morning plotting locality with Benson and putting up 7 D. merriami and the pocket mouse. Afternoon put out 9 gopher sets (19 traps) and observed birds. I found that the gopher diggings vary considerably in differ- ent types of ground. Along the shore of the slough, where the ground is fairly damp, there is a heavy growth of dry grass. The roots of this grass are embedded in a very