Ranges of the 45 wild mammals occuring in southwestern Minnesota are discussed and documented. Eight other species that either formerly occurred in the area or might exist but have not yet been documented also are considered. Seven species are recorded from southwestern Minnesota for the first time: Scalopus aquaticus, Myotis keenii, Lasionycteris noctivagans, Marmota monax, Spermophilus franklinii, Tamiasciurus hudsonicus, and Rattus norvegicus
