"The California Vole occurs throughout much of California and southwestern Oregon, with disjunct subspecies in the Mojave Desert, the White Mountain/Panamint ranges, and northern Baja California. California Voles construct surface runways and extensive underground burrows, and are active throughout the year, chiefly at dawn and dusk. Fresh vegetation clippings and fecal pellets are indicators of the Voles' presence. The size of individuals varies considerably over the range of the species, with males about 6 percent longer and 11 percent heavier than females. Local abundance is also highly variable."
Links:Mammal Species of the World
Original description: Peale, T.R., 1848. U.S. exploring expeditions 1838, 1839, 1840, 1841, 1842 under the command of Charles Wilkes, U.S.N., Mammalogy and Ornithology, p. 44. Asherman and Co., Philadelphia, 8:1-338.