Journal Hafner, M-S. 1977 10 km S, 2 km W Sombrerete, 2130 m, Zacatecas, México. 21 July (cont) distance of 1.9 mi. beyond (sw) of the turn-off to Mesillas, where we camped and set out Gopher traps in the mesquite-grassland. By nightfall we captured 5 Thomomys umbrinus and, due to the coolness of the evening, we decided to leave the traps out overnight. 1900 we set out 100 sherman traps, 50 N of the main road and 50 south (all mesquite- grassland.) The valley (Valle San Antonio) is very beautiful; Much agriculture (cotton?), streams, etc. The railroad passes through the valley to the S of where we camped. We noted many ground squirrels (unidentified), and numerous kangaroo rat holes. Map of locality: Vicente Guerrero 5km N Durango Sukil 45 Chalchihuites Sombrerete Mesillas Trap site Fresnillo