How to Identify Bighorn Sheep in Colorado

Adult male bighorn sheep stand 3 to 3.5 feet at the shoulder and weigh 160 to 250 pounds. Females are noticeably smaller, typically 100 to 140 pounds. Their stocky, powerful build and thick musculature make them heavier than they appear. When you see them on steep cliffs, their compact, muscular frame is one of the first signs you have spotted bighorn and not another large mammal.

Male bighorn sheep horns are the most distinctive feature. The horns curve backward and outward in a shape resembling a full circle or 'C'. An older male may have massive horns that curve almost completely around, creating a coil. The horns are ridged and can grow to 40 inches around the curve. Females have thinner, shorter, slightly upright horns. These horns do not shed and continue to grow throughout the sheep's life.

Bighorn sheep in Colorado have a tan, brown, or gray-brown coat. The exact shade varies with the population and season. Their most striking marking is a white rump patch that stands out, especially when the animal runs or moves up a cliff. The white rump and white patches above the hooves make the sheep visible from a considerable distance in rocky terrain.

Bighorn sheep are expert climbers adapted to steep, rocky slopes and cliffs where few other large animals can travel. They move with a sure-footed, bounding gait across near-vertical rock. Their hooves have rubbery pads that grip stone. In Colorado, you will find them on the faces of canyons, high mountain slopes, and rocky ridges, often far from the valley floor. They are most visible at dawn or dusk when they feed.

Bighorn sheep often gather in herds of 5 to 20 animals, sometimes more. Rams (males) are heavier and have the massive horns. Ewes and lambs are smaller and the lambs are noticeably tiny, following their mothers closely. A lamb born in spring will still be small into late summer. Watching the group composition and horn size helps you confirm you are observing bighorn and determine the sex and approximate age of individuals.

Bighorn sheep droppings are small, pellet-shaped, and rounded. You may find them on trail ledges and flat rocks where the sheep rest. Their hoofprints, showing two rounded toes, appear on soft ground near water sources and cliff bases. In rocky terrain, you might see rub marks on stone where they have worn paths along frequently used routes. Listen for a bleating or snorting alarm call when bighorn sense danger.

Mountain goats and bighorn sheep live in similar high, rocky terrain in Colorado but are not the same animal. Bighorn sheep are stockier and have longer, curved horns that arc backward. Mountain goats are whitish or cream colored and have shorter, sharp, upright horns. Mountain goats also have a distinct beard on their chin. Bighorn sheep have a tan to brown coat and a white rump patch, not a white body. Once you know these differences, telling them apart is straightforward.

Late spring through early fall, from May through September, is when bighorn sheep are most active and visible in high mountain areas. Summer is the peak season for viewing. In fall, they move to slightly lower elevations but remain in steep, rocky terrain. Winter snow pushes some bighorn to windswept ridges and south-facing slopes. Early morning and late afternoon light help you spot them as they feed and travel.

Bighorn sheep are confirmed to occur in and around Rocky Mountain National Park, the San Juan Mountains, and Gunnison Valley. The locations listed on the 'where to see' guide for Colorado bighorn sheep are chosen because they have established or recently sighted populations. Not every trip to these areas guarantees a sighting, but these are the reliable starting points for a bighorn sheep search in Colorado.