Rocky Mountain bighorn rams can weigh up to 340 pounds; the ewes are much smaller. A full grown male may stand over 3 feet tall at the shoulder. For both desert and Rocky Mountain bighorn, the biggest visual difference between the sexes is the horns. Ewe horns are generally 10 to 13 inches long with a circumference of 5 to 6 inches. Ram horns may measure 30 to 40 inches along the outside curl with a basal circumference of 13 to 15 inches. The horn core is honeycombed with chambers, or sinuses, which reduce the weight of the skull.
At their peak, North American bighorn sheep numbers were estimated at 2 million. Desert populations have since fallen to about 20,000 and Rocky Mountain populations are at about 45,000. Arizona’s bighorn population, consisting of both desert and Rocky Mountain races, is estimated at 6,000 animals. The causes for this decline, which occurred primarily between 1850 and 1900, were competition with livestock for food and water and exposure to livestock associated parasites and diseases.
Totally protected by the territorial legislature in 1893, bighorn sheep were not legal game in Arizona until 1953, when it was determined that the limited hunting of desert bighorn rams might be the only way to save these animals. Two limited desert bighorn sheep hunts of 20 permits each were authorized, and 20 desert bighorn were taken. Since then, permit numbers, the number of units open to hunting, the number of rams taken, and hunt success have gradually increased. In 1984, Arizona began offering Rocky Mountain as well as desert bighorn sheep hunts. Between 80 and 100 hunt permits are authorized each year, mostly desert bighorns, with hunt success ranging between 90 and 95 percent.
To conserve Arizona’s diverse wildlife resources and manage for safe, compatible outdoor recreation opportunities for current and future generations.
Rules and regulations for hunting in Arizona.
Regulations for spring hunts, fall hunts and pronghorn, elk hunts.