Bighorn Sheep

A Majestic Animal Under Threat

Bighorn sheep are one of Idaho’s most famous wildlife species. Unfortunately, these majestic animals are in decline.

Bighorn sheep are valued by wildlife enthusiasts, tourists and sportsmen. These iconic animals roam the rugged terrain of the Middle Fork and Main Salmon Rivers, Hells Canyon, and the Owyhee Canyonlands.

Bighorn Sheep Are in Decline

Populations are seriously declining. In central Idaho, numbers of Rocky Mountain bighorn sheep have decreased from 10,000 to fewer than 1,600. Many of the remaining sheep exist in isolated herds consisting of fewer than 100 individuals.

Scientists attribute most of the decline in bighorn sheep numbers to a pneumonia-like disease carried by domestic sheep. The Idaho Conservation League is engaging with U.S. Forest Service and Bureau of Land Management to separate these two species and recover bighorn sheep populations.

Disease Affecting Bighorn Sheep

Scientists attribute most of the decline in bighorn sheep numbers to a pneumonia-like disease. Domestic sheep carry this disease and are resistant to it, but the disease can be fatal to bighorns. Because both species of sheep are naturally gregarious, they can interact and transmit disease when they both occupy the same range. Infected bighorn sheep then spread the disease among their own herds. In 2004, 80% of the lambs in Hells Canyon died from a disease outbreak.

The solution is relatively simple: don’t graze domestic sheep on public land where bighorn sheep live. But this means that ranchers who haven’t adjusted operations in decades may have to adapt and find new pastures for their private sheep operations.

Court Limits Domestic Sheep Grazing

In March, 2016, a court decision limited domestic sheep grazing in order to protect Idaho’s bighorn sheep.