Of 55 bighorn sheep records in North Dakota, 41 come from Theodore Roosevelt National Park alone, and nearly the rest fall in the badlands counties of McKenzie and Billings. This is one of the tightest ranges of any mammal in the state’s atlas, a map drawn almost entirely by the breaks and buttes along the Little Missouri River.
Built for broken ground
A bighorn’s whole design is escape terrain. Rubber-soled hooves grip slick clay slopes, and sheep stay within a short run of steep ground where coyotes and other predators cannot follow. Ewes and lambs band together on the gentler faces through most of the year, while rams range apart and join the herds mainly for the rut. The bands now watched in the badlands descend from sheep reintroduced to western North Dakota in the mid-twentieth century, after the original herds were lost from the state, and the Little Missouri National Grassland and the park’s rugged south unit remain their stronghold.
Two seasons to look
Sheep are present all year, but the record has two clear peaks. July and August bring lambs onto open slopes in the long daylight, and November belongs to the rut, when mature rams gather, posture, and crash horns on the benches in ways that carry across a whole drainage.
Status in North Dakota
NatureServe has not assigned the bighorn a state rank in North Dakota, listing it as SNR, Unranked. The species is native to the state, and USGS NAS does not list it as nonindigenous here.
Full species profile
