Bighorn Sheep in and near Glacier National Park
Bighorn sheep in the American West are a valued big game species and enjoyed by tourists visiting national parks. The populations in Glacier National Park make up one of the largest metapopulations in the continental U.S., and USGS NOROCK scientists have been studying them to inform the management of this charismatic and economically valuable species.
Background
Glacier National Park has one of the largest metapopulations of bighorn sheep in the continental U.S. They are vulnerable to diseases such as pneumonia and many questions remain about how habitat needs, movement, and disease interact. NOROCK scientists are working to improve our understanding of bighorn sheep movements, approaches for monitoring bighorns, and habitat use in Glacier National Park, where the public expects to see bighorns on the landscape. NOROCK scientists collected GPS data as well as genetic and disease samples on over 100 bighorn sheep east of the Continental Divide in Glacier National Park, Waterton National Park, and the Blackfeet Reservation to inform bighorn sheep and wildlife disease management.
Bighorn sheep diets
Bighorn sheep distributions in Glacier National Park overlap with mountain goats, which are declining. Using fecal pellets collected primarily in 2022, NOROCK scientists, in collaboration with the park, are evaluating differences between mountain goat and bighorn sheep diets in the park.
Habitat use and disease risk
NOROCK and National Park Service scientists used GPS data to create a map of habitat use and maps of the probability of inter-group contacts for bighorn sheep. This provided spatial information that Glacier National Park, Waterton Lakes National Park, and the Blackfeet Nation can use for sheep management decisions.
Population Structure and movement
NOROCK and other USGS researchers evaluated the structure of the population based on genetic data. In 2014 the Glacier National Park Conservancy provided funding to genotype blood samples of 100 captured bighorn sheep at 18 microsatellite loci. USGS collaborated with Montana State University researchers and Montana Fish Wildlife and Parks to sequence the same samples and assess kinship and translocation success across the state based on genetic sequence data. Researchers next assessed how fire and other landscape change in forest cover might influence movements between and within subpopulations to inform options for disease, habitat, and population management for Glacier National Park, Waterton Lakes National Park, and the Blackfeet Nation.
The importance of mineral licks
Mineral licks provide important nutrients for the development of strong bones and horns, are important to overall sheep health, and by strengthening immune systems, may buffer sheep from disease (Poole et al. 2026). Because natural mineral licks in Glacier are relatively uncommon, they may represent a limiting resource in this system. NOROCK researchers used GPS collar data from ~95 bighorn sheep to summarize sheep movements towards known mineral licks and assess how these movements compare with other sheep movements. Scientists summarized the timing and frequency of bighorn use of known mineral licks and deployed two different types of remote cameras to evaluate ways of monitoring bighorn sheep at one mineral lick in Glacier National Park.
Bighorn sheep in the American West are a valued big game species and enjoyed by tourists visiting national parks. The populations in Glacier National Park make up one of the largest metapopulations in the continental U.S., and USGS NOROCK scientists have been studying them to inform the management of this charismatic and economically valuable species.
Background
Glacier National Park has one of the largest metapopulations of bighorn sheep in the continental U.S. They are vulnerable to diseases such as pneumonia and many questions remain about how habitat needs, movement, and disease interact. NOROCK scientists are working to improve our understanding of bighorn sheep movements, approaches for monitoring bighorns, and habitat use in Glacier National Park, where the public expects to see bighorns on the landscape. NOROCK scientists collected GPS data as well as genetic and disease samples on over 100 bighorn sheep east of the Continental Divide in Glacier National Park, Waterton National Park, and the Blackfeet Reservation to inform bighorn sheep and wildlife disease management.
Bighorn sheep diets
Bighorn sheep distributions in Glacier National Park overlap with mountain goats, which are declining. Using fecal pellets collected primarily in 2022, NOROCK scientists, in collaboration with the park, are evaluating differences between mountain goat and bighorn sheep diets in the park.
Habitat use and disease risk
NOROCK and National Park Service scientists used GPS data to create a map of habitat use and maps of the probability of inter-group contacts for bighorn sheep. This provided spatial information that Glacier National Park, Waterton Lakes National Park, and the Blackfeet Nation can use for sheep management decisions.
Population Structure and movement
NOROCK and other USGS researchers evaluated the structure of the population based on genetic data. In 2014 the Glacier National Park Conservancy provided funding to genotype blood samples of 100 captured bighorn sheep at 18 microsatellite loci. USGS collaborated with Montana State University researchers and Montana Fish Wildlife and Parks to sequence the same samples and assess kinship and translocation success across the state based on genetic sequence data. Researchers next assessed how fire and other landscape change in forest cover might influence movements between and within subpopulations to inform options for disease, habitat, and population management for Glacier National Park, Waterton Lakes National Park, and the Blackfeet Nation.
The importance of mineral licks
Mineral licks provide important nutrients for the development of strong bones and horns, are important to overall sheep health, and by strengthening immune systems, may buffer sheep from disease (Poole et al. 2026). Because natural mineral licks in Glacier are relatively uncommon, they may represent a limiting resource in this system. NOROCK researchers used GPS collar data from ~95 bighorn sheep to summarize sheep movements towards known mineral licks and assess how these movements compare with other sheep movements. Scientists summarized the timing and frequency of bighorn use of known mineral licks and deployed two different types of remote cameras to evaluate ways of monitoring bighorn sheep at one mineral lick in Glacier National Park.