We revisited 26 of the 28 known collection sites for the California vole, Microtus californicus, in Baja California, Mexico. With live trapping, we were able to confirm the continued presence of the vole at 7 of these sites, which include all 3 of the subspecies endemic to Baja California. At 14 of these sites, no viable habitat was found. These 14 sites included all known occurrences of M. californicus sanctidiegi in Baja California. Based on capture numbers or lack of habitat, population size may be drastically reduced at all sites except one. Effective conservation actions are required for recovery of California vole populations in Baja California.