Phuong, M. A., Lim, M. C., Wait, D. R., Rowe, K. C., & Moritz, C. (2014). Delimiting species in the genus Otospermophilus (Rodentia: Sciuridae), using genetics, ecology, and morphology. Biological Journal of the Linnean Society, 113(4), 1136-1151.
"Sierra Nevada with its Northern limit at Lake Almanor. South from the Sacramento-San Joaquin River Delta, into the Central Valley, with its southernmost extent in Baja California. Includes an allopatric population in Baja California Sur. Type locality: ‘neighbourhood of San Francisco and Monterey, in California’."