Class Mammalia Linnaeus, 1758 - mammals
   Subclass Theria Parker & Haswell, 1897
     Order Artiodactyla Owen, 1848 - even-toed ungulates see Order Cetartiodactyla Montgelard, Catzeflis & Douzery, 1997
       Family Cervidae Batsch, 1788 - deer
         Subfamily Capreolinae Brookes, 1828
           Genus Odocoileus Rafinesque, 1832 - white-tailed deer and mule deer
             Odocoileus hemionus (Rafinesque, 1817) - mule deer
               Odocoileus hemionus columbianus (Richardson, 1829)