Mule deer (Odocoileus hemionus) fawn, Pike National Forest, Colorado, USA - stock photo

The mule deer (Odocoileus hemionus) is a deer indigenous to western North America; it is named for its ears, which are large like those of the mule. The several subspecies include the black-tailed deer. Unlike the related white-tailed deer (Odocoileus virginianus), mule deer are generally more associated with the land west of the Missouri River, and more specifically with the Rocky Mountain region of North America. The mule deer is the larger of the two Odocoileus species on average, with a height of 80-106 cm at the shoulders and a nose-to-tail length ranging from 1.2 to 2.1 m. Of this, the tail may comprise 11.6 to 23 cm. Adult bucks normally weigh 55-150 kg, averaging around 92 kg, although trophy specimens may weigh up to 210 kg. Does (female deer) are rather smaller and typically weigh from 43 to 90 kg, with an average of around 68 kg.