Colorado is home to the largest population of bighorn sheep in the United States. These majestic animals, whose males are known as rams, are not just common wildlife but are also recognized as Colorado’s official state animal. The presence of these iconic sheep is deeply tied to the state’s rugged mountain geography. This article will explore how to identify these sheep, where their specific habitats lie, details of the rams’ unique biology, and the efforts underway to protect them.
The Rocky Mountain Bighorn Sheep
The species found throughout Colorado is the Rocky Mountain Bighorn Sheep. This subspecies is recognizable by its coat that ranges from light brown to grayish-brown, contrasted by a distinct white patch on the rump and muzzle. Males, or rams, are notably larger and heavier than the females, called ewes, with mature rams weighing between 160 and 300 pounds.
The most striking feature is the massive, coiled horns that give the animal its name. Ewes also possess horns, but theirs are significantly shorter, thinner, and only slightly curved. These sheep are perfectly adapted to their steep environment, possessing specialized hooves with hard outer edges and soft inner pads that provide exceptional traction on rocky, slippery terrain. Their physical adaptations allow them to navigate the precipitous cliffs and ledges that serve as their primary refuge from predators.
Key Habitats and Geographic Distribution
Bighorn sheep are obligate users of precipitous terrain. They are distributed throughout the central and western mountain ranges of Colorado. Well-known viewing areas include the mountainous terrain near Mount Evans, Pikes Peak, and the popular Georgetown Herd near the town of Silver Plume.
Their movement is strongly dictated by seasonal changes and food availability, a pattern known as vertical migration. During the summer, herds typically move to higher elevations, often grazing on alpine meadows and slopes between 6,000 and 14,000 feet. As heavy winter snows arrive, they descend to lower, wind-swept elevations, seeking out south-facing slopes and canyon areas, with winter ranges sometimes dropping to 2,500 feet. This seasonal shift ensures access to forage and avoids the deep snowpack they cannot easily traverse.
Ram Biology and Social Behavior
The ram’s massive horns are a defining characteristic, made of keratin and growing continuously throughout the animal’s life. A mature ram’s horns can weigh up to 30 pounds. The horns develop growth rings, called annuli, which can be counted to estimate the ram’s age, with a new ring forming annually during the rutting season.
For most of the year, mature rams live separately in small groups known as bachelor herds. This separation ends during the rut, the late fall and early winter mating season that runs roughly from October through January. During this time, rams compete aggressively for breeding rights by engaging in spectacular, high-impact head-butting clashes.
These dominance rituals establish a clear hierarchy, with the largest rams possessing the greatest horn size doing most of the breeding. The ram’s double-layered skull absorbs the tremendous shock of these collisions, which can occur at speeds up to 20 miles per hour.
Conservation Status and Public Viewing
Colorado Parks and Wildlife (CPW) estimates the statewide population to be over 7,000 animals, a significant recovery from the near-extinction levels reached in the early 1900s due to disease and unregulated hunting. Despite this success, the species is still listed as a species of greatest conservation need, facing ongoing challenges.
The primary threats to the herds involve habitat fragmentation and the risk of disease transmission, particularly respiratory pathogens spread by domestic sheep. CPW utilizes methods like trapping and relocation to establish new herds and maintain a healthy distribution across the state. For the public interested in observing these animals, it is best to focus on known areas like Rocky Mountain National Park or the Georgetown area, especially during the fall rut when rams are more visible.
When attempting to view bighorn sheep, observers should always use binoculars or a spotting scope and maintain a respectful distance to avoid stressing the animals. Their need for undisturbed access to steep terrain for escape is paramount, so any interaction should prioritize their safety and natural behavior.