Sierra Nevada bighorn sheep were important to indigenous peoples, as numerous rock-art depictions of the legendary animals are found throughout the Owens Valley. Over the past century and a half, the herds declined drastically, allowing the Sierra bighorn sheep to be placed on the U.S. endangered species list. However, collaborative efforts between several organizations have prevented further herd declines, providing visitors the opportunity to view these creatures in their natural habitat.
What are Sierra Nevada Bighorn Sheep?
The characteristic horns of the Sierra bighorn sheep display are less curved and much broader than their Rocky Mountain cousins. The keratin horns of both rams (males) and ewes (females) continuously grow and are never shed, becoming more impressive as the sheep ages. During the breeding season in mid to late autumn, rams use their horns in displays of dominance. Throughout the fall, hikers might hear the sharp crack of head-butting rams as the sound echoes across the remote canyons of the Sierra Nevada.
Sierra Nevada bighorn sheep have a lifespan of 12 to 20 years in the wild. Ewes may weigh up to 155 pounds (70 kg) while stout rams may reach 220 pounds (100 kg). These high-altitude large mammals are herbivores, so their migration patterns are dependent on seasonally controlled vegetation. Today, the modern habitat range of the Sierra bighorn spans from north of Yosemite National Park to Mount Whitney near Lone Pine, CA.
Where to See Sierra Nevada Bighorn Sheep
Finding a herd of Sierra bighorn is highly dependent on the season and snow depth. In the winter months, the bighorn travel to the lower flanks of the mountains between 7,000 to 9,000 feet in elevation. Once the high-alpine snow melts in the summer, the sheep migrate to remote areas perched at elevations between 10,000 to 14,000 feet. Bighorn sheep are elusive, and their fur blends into the surrounding landscape very well, providing them with some of Mother Nature's best camouflage. They also have keen eyesight in order to spot predators, so it can be difficult to view a herd in close proximity. At all times when in a bighorn habitat, please do not disturb these unique and federally protected mammals in any way.
The best chance to spot a bighorn is when the herds migrate to their winter ranges. The Pine Creek area, located 25 miles south of Mammoth Lakes, is one of the best locations to view wintering bighorns. Bring your binoculars or spotting scope, as the only way of spotting the herd is from a distance. Look for movement among rocks, boulders, and cliffs around the mouth of the Pine Creek canyon. Check out this map from the California Department of Fish and Wildlife website to find easily accessible viewing areas of the bighorn winter range.
During the summer, the bighorn's range is limited to mountain ridges deep within the mountains of the Sierra Nevada. The high-altitude areas of Badger Pass, Cottonwood Lakes Basin, and Mount Langley are known to be prime bighorn habitats in the summer months. This map from the California Department of Fish and Wildlife website shows the known summer ranges of bighorns in the Cottonwood Lakes Basin.
Sierra Nevada Bighorn Sheep Conservation
The species was on the brink of extinction in the 1990s when a major preservation effort led by biologist Dr. John Wehausen placed the sheep on the U.S. endangered species list. This federal protective status was designated in just three months, which is a reflection of how imperiled the subspecies of bighorn sheep was at this time. Throughout the 20th century, the herds declined as a result of human impacts, such as disease (pneumonia) spread by domestic grazing sheep, over-hunting and habitat disturbance. Bighorn transfer and reestablishment in the 1980s led to herd expansion in portions of the sheep's historic range.
In order to preserve the bighorn sheep, biologists spent years studying the animals’ ecosystems, movements, and reproduction. Radio collaring allows biologists to track the movements of both bighorn sheep and predatory mountain lions, allowing for data collection and removal of problematic predators. More recently, the rezoning of grazing permits is preventing the spread of disease between domestic livestock and wild sheep.
In the mid 1990s, the Sierra Nevada bighorn sheep herd was comprised of only 100 adults. Today, the population has rebounded and is believed to number in the 600s. While this is a dramatic increase and reflects the efforts of many conservationists and biologists, the Sierra bighorns are still at risk. Be aware that during the big horn migratory season, the federal and state governments may close certain wilderness for human travel in order to eliminate the potential for interference.
