Project overview: Continue work toward saving endangered Sierra Nevada bighorns by translocating individuals, tracking populations, and building resilience in the three Yosemite-area herds of wild sheep.

How your support helps: Sierra Nevada bighorn sheep live only in their namesake mountain range. They 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 under way 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, establishing herds on Mt. Warren and Mt. Gibbs. In 2015, again with donors’ help, biologists helped establish a third 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 pursue a long-term goal of ensuring the species’ survival and self-sufficiency. Scientists monitor the sheep, both remotely and through fieldwork, carefully bring in rams and ewes from other parts of the species’ range, and work to educate the public about the bighorns’ story. In 2021, surveys found 18 lambs across three herds — a welcome sign after unusually harsh winters in recent years, which threatened the sheep’s survival. 

This year: This year, your support will enable the bighorn team to respond to winter 2023 mortalities by considering translocating bighorns into Yosemite’s herds, tracking population fluctuations and habitat use with ground observations and GPS collars, and communicating this species’ incredible survival story. This project will boost the herds’ long-term persistence and ensure bighorns are one step closer to recovery and successful removal from the endangered species list.

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

Sarah Stock

Wildlife Biologist, Yosemite National Park

Project Notes

"The species, the park and the public benefit from this project. With targeted reintroductions, Sierra Nevada bighorn sheep are one step closer to recovery."