How to Identify Bighorn Sheep in Nevada

Bighorn sheep are large, heavily built wild sheep with stocky bodies and powerful legs. Adult males typically weigh 150 to 200 pounds and stand about 40 inches tall at the shoulder; females are noticeably smaller and more delicate, weighing 100 to 140 pounds. Both sexes have greyish-brown to tan coats with a lighter rump patch and pale belly. The coloring varies by individual and location but is rarely pure white and never dark brown or black. Their most distinctive feature is the massive curved horns on males, which spiral backward and outward in a full circle, sometimes making a complete 360-degree turn. Female horns are much shorter and thinner, curving back slightly but never reaching the dramatic spiral of males.

Male bighorn sheep horns are the defining field mark and vary dramatically with age. Young males have short, straight spikes. By age 4, horns curve back and begin the spiral. By age 6 or 7, they form a tight, nearly complete circle. Older males develop massive, thick horns that may spiral past a full circle, sometimes curling even tighter. The tips are often worn flat and blunt from rubbing on rocks. Horn thickness increases with age, so an old male has thick, deeply ridged horns that look chunky at the base. Rams also develop prominent horns with a ridge running up the back and spiral grooves along the sides. The color of horns is similar to the body, ranging from light tan to brown. A fully curled horn on a large male is unmistakable and can be seen from great distances with binoculars.

Bighorn sheep are leaner, more muscular, and more athletic than domestic sheep. Domestic sheep have wool that is often white or cream colored and very thick, making them appear puffy and soft. Bighorn sheep have short, coarse hair that lies close to the body, showing their muscular structure. Bighorn sheep lack the fat deposits on their tails and hind quarters that many domestic breeds carry. The head shape is different too. Bighorn sheep have a narrower, more refined face and prominent facial features, while domestic sheep often have broader, blunter faces. Bighorn sheep also lack the dangling dewlap or other fleshy features that some domestic breeds possess. In Nevada, bighorn sheep are wild and free-ranging, found only in remote mountain terrain, while domestic sheep are kept on ranches or in pastoral settings. If you see a sheep in the backcountry far from any civilization, it is almost certainly a bighorn.

Yes, both male and female bighorn sheep have horns, but they are dramatically different in size and shape. Female horns are short, thin, and slightly curved, typically measuring 12 to 18 inches in length. They curve back and upward in a gentle arc and never develop the tight spiral or full curl seen on males. A female's horns are so small that from a distance they are often invisible, and at first glance a female may appear to have no horns at all. The short horns help distinguish females from males, which are the easiest way to sex a bighorn from afar. Females also appear slimmer overall compared to the stocky, powerful build of males. The smaller horn and leaner body shape together make female bighorn sheep look completely different from the massive, horned rams that capture most photographers' attention.

Bighorn sheep tracks are circular or oval hoofprints about 2 to 3 inches long and 1.5 to 2 inches wide. The hooves are sharp and narrow, designed for gripping steep rock, so tracks in soft ground are deep and precise. Tracks are smaller than mule deer tracks (which are more pointed and narrow) and larger than mountain goat tracks (which are more angular). On rocky terrain, you may see scuff marks and small rock debris disturbed by the precise placement of hooves. Bighorn sheep droppings are pellets, similar to deer scat but often larger and clustered. The pellets are dark brown or black and about the size of a pea or bean. On steep rock faces and ridges where sheep frequent, you may see worn trails where repeated hoof traffic has polished the stone. Salt licks and mineral-rich soil patches may have exposed hoofprints and concentrated droppings. The steep, rocky terrain where tracks appear is often the best clue that the prints belong to a bighorn sheep rather than another wild ungulate.

Bighorn sheep are generally quiet animals but make several vocalizations. They produce sharp, loud bleats, ranging from a high-pitched bleat of a lamb to a deeper bleat of an adult. During the breeding season (August through November), rams vocalize more frequently. Males also produce low, guttural sounds during conflict or dominance displays. A common sound is a loud snort or exhale of air, used as an alarm when alarmed or stressed. During fights, rams produce loud crashing sounds when their horns collide at full speed, audible from hundreds of yards away. In quiet backcountry, the sound of hooves on loose rock and scree can alert you to sheep movement. Lambs vocalize more frequently than adults, bleating for their mothers. Most of the time, however, bighorn sheep are silent, making them difficult to locate by sound alone. Binoculars and patient scanning of rocky slopes are more reliable methods than listening.

Age can be estimated by overall body size and horn development in males, though exact aging requires expertise. Lambs are noticeably small and woolly, often staying close to their mothers through their first year. Yearlings are larger but still relatively small, and males begin growing horn spikes. Two-year-old males have small horns beginning to curve. By age 4 or 5, males are nearly full grown and horns have formed a half-circle or better. Fully mature males (age 7 and older) are large and muscular with massive, deeply curved horns. Females grow more slowly and remain noticeably smaller than males throughout their lives. The body shape also indicates age. Young sheep have leaner, more angular faces and bodies. Older males develop heavier bodies and thicker necks. Females are difficult to age in the field without experience, as they do not develop the dramatic horns that mark male age. An old female may be distinguished from a young female by her slightly larger body and more robust appearance, but the difference is subtle.

Bighorn sheep are found only on steep, rocky terrain where they can navigate cliffs and rocky outcrops that predators cannot reach. They prefer mountain ranges, canyon walls, and talus slopes with exposed rock. In Nevada, they occupy high elevation ranges such as the Ruby Mountains, Great Basin ranges, and rocky areas around Lake Mead and Red Rock Canyon. They bed down in rocky crevices, on narrow ledges, or in cliff alcoves where they are hidden and can escape quickly. During the day, sheep are often on high, exposed ridges and rocky faces where visibility is good. They descend to water sources in the early morning and late evening, visiting springs, seeps, and streams. They graze on grasses, herbs, and shrubby vegetation on rocky slopes and meadows but rarely venture far from cliffs. In winter and spring, they move to lower elevation slopes to access fresh forage. In summer, they may move higher. Rocky, inaccessible terrain is the key to finding them. Sheep spend most of their time on or very near steep rock faces where humans on foot are limited in access.

Mountain goats and bighorn sheep both live on steep terrain but are quite different. Mountain goats are smaller, more compact, and pure white or cream in color. Their horns are short, thin, and backward-curving, never spiraling. Goats have a stockier, more compact body and very thick, shaggy coats. Bighorn sheep are larger, heavier, and tan to brown in color. Male bighorn sheep have massive, deeply curved or spiraling horns that are much larger than goat horns. Sheep also have shorter, coarser hair. Mountain goats are found in higher elevation terrain and are more nimble on extreme vertical cliffs. Bighorn sheep prefer rocky slopes, canyon walls, and ranges but are less specialized for extreme climbing. In Nevada, mountain goats are rare or absent, while bighorn sheep are the wild ungulate found on rocky terrain. If you see a brown or tan animal on a steep slope in Nevada, it is almost certainly a bighorn sheep. A white, shaggy animal would be a mountain goat if present, but goats are not established in Nevada.

Start by scanning rocky ridges, cliff faces, and talus slopes with binoculars, especially in early morning and late evening. Look for the distinctive curved horns of males, which are visible from great distances and stand out against the sky or rock. The light-colored rump patch is also a reliable spotting feature. Scan ledges and cliff alcoves where sheep bed down. Watch for movement or the flash of white on the rump as an animal shifts position. On steep slopes, focus on areas where sheep can stand without being exposed to predators from below. The spine of ridges and high, rocky outcrops are favorite daytime spots. Sheep often stand completely still, which makes them hard to spot until they move. Use a methodical, slow scan of the terrain rather than quick glances. Patient observation with 8x to 10x binoculars will reveal sheep that are invisible to the naked eye. Early morning light can silhouette sheep against the sky, making horns very obvious. If you see one sheep, scan nearby as sheep often travel in small groups.