North Dakota Reports Highest Bighorn Sheep Population on Record

Bighorn sheep are an iconic species in the United States, with well-defined horns and specialized hooves and rough soles that help them latch onto rocky cliffs with ease. The population had dipped in North Dakota following a disease outbreak, but the latest count shows the species at its highest numbers on record in the state.

The North Dakota Department of Game and Fish says its 2020 count found a total of 322 sheep in the western part of the state, up 11% from the prior year and 13% higher than the five-year average. It also eclipsed the prior record of 313 set in 2008. The count didn’t include 40 sheep in the North Unit of Theodore Roosevelt National Park or those recently introduced to the Fort Berthold Indian Reservation.


Big game biologist Brett Wiedmann says, “We were encouraged to see the count of adult rams increase after declining the last four years, and adult ewes were at record numbers. Most encouraging was a record lamb count corresponding with a record recruitment rate.”

The numbers rebounded after bacterial pneumonia first detected in 2014 killed about three dozen sheep. State Wildlife Chief Jeb Williams notes that it can take 15 years for pneumonia to work its way out of a herd.

Overall, the state is reporting more than 400 bighorn sheep in populations managed by the North Dakota Game and Fish Department, the National Park Service, and the Three Affiliated Tribes Fish and Wildlife Division. According to Wiedmann, the species was wiped out in the state by 1905, when the last confirmed native bighorn sheep was killed. President Theodore Roosevelt visited in the 1880s and said they were scarce at that time.

Wiedmann says that makes 2020’s numbers all the more impressive, explaining, “So, it’s likely there are more bighorns today than before North Dakota’s statehood in 1889. It really illustrates the historical significance of this year’s count.”


At the same time, the southern Badlands population of the state, located south of Interstate 94, is down to about 15, due to several other pneumonia outbreaks and insufficient lamb recruitment. Worsening the problem is that domestic sheep can pass the pneumonia to their wild brethren, and wildlife officials say introducing healthy animals to a herd where the disease is already present won’t help the population grow. The plan is to eliminate the dwindling herd and bring healthy bighorn from Rocky Boy’s Indian Reservation in Montana in their place, but there is not a set timeline for that.

The animals transplanted to Fort Berthold last year, from the same spot in Montana, did well. Among the original 30, only one died, and there were 19 lambs recruited. As a result, the population increased to 48.

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How many could there be in each area of the state?

Wiedmann explains, “It’s a very realistic possibility that we could eventually have 500 bighorn sheep in the northern badlands where there is a lot more suitable habitat than down south. And, you know, we’d be pretty happy if we ultimately had 75 bighorns south of the interstate.”

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