Project goal: Monitor and grow the Cathedral Range bighorn herd, with the long-term goal of establishing a self-sustaining population of endangered wild sheep in the Yosemite Wilderness.

Why this work matters: Sierra Nevada bighorn sheep, the agile alpine mammals that John Muir ranked “highest among the animal mountaineers of the Sierra,” live only in their namesake mountain range — and are slowly reclaiming a foothold in those high peaks, after decades on the edge of extinction.

Bighorns vanished from Yosemite in 1914, due largely to disease, hunting and predation. Long before the species was declared federally endangered in 2000, efforts were underway to save the Sierra’s wild sheep. In the 1980s, with support from our donors, the National Park Service reintroduced Sierra Nevada bighorn sheep near Yosemite’s eastern border. In 2015, again with donors’ help, biologists released a bighorn herd in the Cathedral Range, marking a milestone: the first wild sheep in the heart of the Yosemite Wilderness in more than 100 years.

Since then, our supporters have helped an interagency team work toward a long-term goal of ensuring the Cathedral Range herd’s survival and self-sufficiency. Despite unusually harsh winters in recent years, the herd has held on. In 2020, the team focused on helping the herd grow and build resilience. They used GPS collars and on-the-ground surveys to track, count and check the health of Yosemite’s bighorn, and they introduced more sheep to increase the herd’s size and genetic diversity.

How your support helped: Your gifts helped scientists complete seasonal surveys of the three Yosemite-area bighorn herds. They counted several dozen sheep, including multiple lambs. Researchers also collected sheep pellets to use in studying the population’s genetics, and released several ewes into the herd in the Mt. Warren area. By supporting this work, you made a difference for the future of an iconic, endangered Sierra Nevada species.

Project partners: Yosemite National Park, California Department of Fish and Wildlife, and Sierra Nevada Bighorn Sheep Foundation.

Sarah Stock

Wildlife Ecologist, Yosemite National Park

Project Notes

"Our goal is to establish the Cathedral Range bighorn herd as a self-sustaining population in the heart of the Yosemite Wilderness. Through targeted augmentations and careful monitoring, we will boost population growth of the newly established Cathedral herd, bringing the species even closer to successful removal from the endangered species list."