Chattin, J. 1940 Itinerary 10 mi. SE Fortuna Mine, 300 ft., Yuma Co., Ariz. The wash and out onto the plain. Dec. 31 a.m. - Trap line was taken up. Catch consisted of 1 Neotoma (prep. C. Schley) [taken in rocks], 1 Dipodomys deserti, 6 Dipodomys merriami (caught out on open creosote bush plain) and 2 Peromyscus caught along base of rocky hill slope. Camp was then moved to locality designated as 16 mi. SE Fortuna Mine, 300 ft., Yuma Co., Ariz. Camp is located near shallow broad wash 1 1/2 mi. E of Butler Mts. In p.m. 75 traps were set out in the rocks at base of these mts. and in sandy country between the mts. and camp. Vegetation is creosote bush association with Ochitillo, cholla and Saguaro cacti spaced at intervals. The Butler mts are light colored granite and rise abruptly from the creosote bush plain. Jan. 1. 1941 a.m. - Trap line was picked up. Catch consisted of 5 Dipodomys deserti, 9 Dipodomys merriami, 1 Peromyscus crinitus and 2 Peromyscus maniculatus? These were skinned during early p.m. and in later p.m. a line of 75 mouse traps and 6 rat traps were set out mainly with intention of catching D. deserti. Jan 2. a.m. Trap line was picked up. 7 traps were lost, apparently carried away by D. deserti and