22 The Mammals of Colorado 
of the books on the habits of the animals bear witness to the 
same fact. On the contrary an antelope has excellent sight, 
and can recognize an enemy at a long distance, and its eyes 
stand out so prominently from the side of its head that it 
probably has a wide field of vision. 
Odocoileus hemionus (Gr. hemionos, mule). Mule 
Deer. Black-tailed Deer. 
Cervus hemionus Rafinesque, Amer. Monthly Mag., i., p. 436 
(1817). 
Type locality. — Sioux River, probably on eastern border of South 
Dakota. 
Measurements. — Total length 68; tail vert., 6; height at withers, 
42; length of antlers around outer curve from 16 up. A specimen 
in the Colorado Museum of Natural History at Denver, killed in 
Rio Blanco County in 1908, had an extreme spread of 39 ins.; 
the right antler measured 27^ and the left 28I ins., around the outer 
curve; the antlers measured 5I ins. in circumference at base; there 
were 13 points on the right and 12 on the left. This is a very 
unusual set of horns, even if not the record, the spread especially 
being very wide. A pair of horns found by J. W. Frey and myself 
hanging on a corral fence near Douglas Spring, Routt County, 
has a total of 34 points. 
Description. — In summer pale dull yellowish or yellowish tawny; 
this is replaced in the autumn by a bluish gray coat, growing 
lighter in color as the hairs lengthen in winter. A dark brown 
patch on forehead between the eyes and extending below them on 
the face; remainder of face and throat white, as are also the ab- 
domen, inner side of legs and buttocks; rest of underparts blackish 
brown; tail white; tip black; ear bordered with black anteriorly. 
Distribution. — Beginning at about W. Lon. 102° in the Dakotas, 
Kansas, Nebraska, and Oklahoma, the Mule Deer has a range 
to the west into the eastern portions of British Columbia, Washing- 
ton, Oregon, and California; there is also an eastwardly extending 
tongue along our northern border in Minnesota and Manitoba 
to about Lon. 95°. It also ranges from Lat. 57° in Alberta south 
into northern New Mexico. This is for the typical form ; there are 
subspecies which carry the range much farther south into Mexico 
and Lower California. 
In Colorado it is found in probably every county from the east 
base of the foothills west to the Utah line. We have no records 
of its occurrence in any of the plains counties at present. 
