Class Mammalia Linnaeus, 1758 - mammals
   Order Rodentia Bowdich, 1821 - rodents
     Suborder Sciurognathi (Tullberg, 1899) see Suborder Sciuromorpha Brandt, 1855
       Family Muridae Batsch, 1788 - rats, mice, hamsters, voles, lemmings, and gerbils
         Subfamily Arvicolinae Gray, 1821 - voles
           Genus Clethrionomys Tilesius, 1850 - red-backed mice
             1 Clethrionomys californicus (Merriam, 1890) - western red-backed vole
             2 Clethrionomys centralis Miller, 1906
             3 Clethrionomys gapperi (Vigors, 1830) - Gapper's red-backed vole
             4 Clethrionomys glareolus (Schreber, 1780) - bank vole
             5 Clethrionomys rufocanus (Sundevall, 1846) - grey red-backed vole
             6 Clethrionomys rutilus (Pallas, 1779) - northern red-backed vole
             7 Clethrionomys sikotanensis (Tokuda, 1935)