Order Rodentia - Family Muridae Author Guy G. Musser Author Michael D. Carleton text 1993 Smithsonian Institution Press Washington and London Editor Don E. Wilson Editor DeeAnn M. Reeder Mammal Species of the World (2 nd Edition) 501 755 book chapter http://doi.org/10.5281/zenodo.7353098 1-56098-217-9 7353098 Microtus townsendii (Bachman, 1839) . J. Acad. Nat. Sci. Philadelphia , 8:60 . TYPE LOCALITY: USA , Oregon , Multnomah Co., Wappatoo (Sauvie) Island , lower Columbia River near mouth of Willamette River (as located by Bailey, 1900:46 ) . DISTRIBUTION: Pacific northwest, from extreme SW British Columbia , Canada , to NW California , USA , including Vancouver and neighboring islands. SYNONYMS: cowani, cummingi, laingi, occidentalis , pugeti, tetramerus . COMMENTS: Subgenus Mynomes , pennsylvanicus species group sensu Zagorodnyuk (1990) . Broadly allied with M. pennsylvanicus and M. nwntanus ( Anderson, 1959 ; Hooper and Hart, 1962 ; Modi, 1987 ), though precise cladistic picture unresolved. See Comely and Verts (1988 , Mammalian Species, 325).