Black-tailed deer once ranged at least as far as Wyoming. In Francis Parkman's The Oregon Trail, an eyewitness account of his 1846 trek across the early West, while within a two-days ride from Fort Laramie, Parkman writes of shooting what he believes to be an elk, only to discover that he has killed a Black-tailed Deer.
It is sometimes classified as a subspecies of the mule deer, as reflected in its scientific name Odocoileus hemionus columbianus as compared to the Rocky Mountain mule deer's Odocoileus hemionus hemionus. However this classification is not widely followed.
The Black-tailed deer is currently common in northern California, western Oregon, Washington, coastal British Columbia, and north into the Alaskan panhandle. There remains confusion, however, over its proper classification. It is a very popular game animal. It thrives on the edge of the forest, as the dark forest lacks the underbrush and grasslands that the deer prefers as food, and completely open areas lack the hiding spots and the cover it prefers for harsh weather. It often is most active at dawn and dusk, and is frequently involved in collisions with automobiles.