Rams typically measure 160-180 cm from head to tail, while ewes are approximately 150 cm.
Bighorn sheep have double-layered skulls shored with struts of bone for battle protection.
They also have a broad, massive tendon linking skull and spine to help the head pivot and recoil from blows. Horns may way as much as 14 kg, which is the weight of all the bones in a ram's body. The horns of a female are much smaller and only slightly curved. The horns of a ram can tell much about him such as his age, health, and fighting history. The desert subspecies, Ovis canadensis nelsoni, is somewhat smaller and has flatter, wider-spreading horns.