Two forms of black-tailed deer or blacktail deer that occupy coastal woodlands in the Pacific Northwest of North America are subspecies of the mule deer (Odocoileus hemionus). They have sometimes been treated as a species, but virtually all recent authorities maintain they are subspecies.The Columbian black-tailed deer (O. h. columbianus) is found in western North America, from Northern California into the Pacific Northwest of the United States and coastal British Columbia in Canada. The Sitka deer (O. h. sitkensis) is found coastally in British Columbia, southeast Alaska, and southcentral Alaska (as far as Kodiak Island).