Davis 40. 61. 7 mi. NE Fort Yuma, 200'; Imperial Co., Calif. Dec. 26. to camp. Set trap line in the Bermuda grass along a ditch bank, at the edge of the arrow-weed growing along the top of the bank. The grass was full of Sigmodon runways. Libby obtained 30+ gophers (T. bottae albatae) from George Berry of Bard. Skinned after dark. Dec. 27. Picked up line near Laguna Dam. I lost 3 traps and Libby lost 2. Others were sprung and dragged. Evidently a carnivore, probably a kit fox, ran on lines. Ditch line produced Sigmodon, Mice, & Reithrodontmys. Skinned a.m. In early p.m. went to the rock covered flats on other side of All-American Canal and set traps in rock-strew washes. Vegetation sparse. Ocotillo & creosote bush. Wood rat sign seen. In one wash numerous fresh burrows, probably of Dipodomys and Perognathus. These were in the sandy floor of the wash. Sign was only fair on the rock covered banks. Returned to camp & ran ditch line. More Sig-modon, etc. drove to Bard & obtained 30+ gophers from Berry. Skinned p.m. Dec. 28. Ran trap line in wash north of Potholes. Several Peromyscus (cinitus?) and 1 Dipodomys merriami. Picked up line. Picked up ditch line near camp. No Sigmodon. Several Mice and Reithrodont-mys. Skinned a.m. Picked up Berry's gopher