Microtus canicaudus Miller, 1897 . Proc. Biol. Soc. Wash., 11:67.

TYPE LOCALITY: U.S.A., Oregon, Polk Co., McCoy .

DISTRIBUTION: Restricted to Willamette Valley, Oregon, and adjacent Washington (U.S.A.).

COMMENT: Subgenus Microtus; closely related to montanus and formerly considered conspecific; Hsu and Johnson, 1970, J. Mammal., 51: 824-826, provided evidence of specific distinctness. See Maser and Storm, 1970, A Key to the Microtinae of the Pacific Northwest, O.S.U. Book Stores, Corvalis, Oregon, for status and distribution.