W.B.Davis 1935. Head Big Lost River, 7895 ft., Custer Co., Idaho. 447 July 11 This a. m. the traps on the Jerome co. side of the river held 1♂, 1♀ Peromyscus crinitus and 1♂, 2♀ Peromyscus maniculatus. All the females contained embryos. On the Twin Falls side of the river the traps held 1♂, 1♀ Peromyscus crinitus and 1♂, 4♀ Neotoma cinerea. The Peromyscus ♂ contained embryos. I broke camp about 6:30 a.m. after getting the specimens and wrapping them in a damp sack and drove to this locality via, Hansen Bridge, Shoshone, Bellevue and Ketchum, Just after I left camp and near the top of the canyon wall I saw a y.g. Marmota flaviventris. It appeared to be as dark as those found on the N. side of the river at Hagerman. Also saw one 7 mi. N of Shoshone in the lava beds). I stopped at a ranch house about 15 mi. N of Shoshone and asked about C. mollis and Thomomys. The rancher said there were lots of the former near Richfield, but very few near his ranch. He said they had never been there that he could remember. He said there were a few small brown gophers in his)