Microtus californicus (Peale, 1848) is a cricetid commonly called the California vole or California meadow mouse. A sexually dimorphic, medium-sized vole, M. californicus is 1 of 62 species in the genus Microtus. It is found in the interior valleys of southwestern Oregon, most of California, and northern Baja California, Mexico. M. californicus is found in a wide range of habitats from arid uplands to wet meadows and salt marshes. Several subspecies are listed as of conservation concern; the Amargosa vole, M. c. scirpensis, is listed as federally endangered.