Bighorn sheep vs domestic sheep on public lands

Wild bighorn sheep once were found throughout the West. Roaming high alpine ridges of the Rockies to the badlands of the Dakotas to the deserts of Arizona and California, bighorns were adapted to a wide variety of climates and terrain and some estimate they numbered in two million or more animals.

But these iconic western animals were decimated by overhunting and competition for forage and space with domestic livestock.

Further reductions occurred to even isolated bighorn herds due to respiratory diseases like pneumonia, a disease that domestic sheep regularly transmit to their wild cousins with disastrous consequences. With little resistance to the disease, often entire herds will be eliminated once a single animal is infected by the disease.

This is not unlike the situation faced by the introduction of smallpox into Native American villages whereby the indigenous people had almost no resistance to the disease and many people died once the disease was contracted.

Wild bighorn rams wander widely during the rut and often will come into contact with domestic sheep if they are anywhere in the vicinity. All it takes is one contact, and the wild ram can bring the disease back to his home turf and transmit the disease to the rest of the flock.

During the initial phases of these outbreaks, large mortalities occur across all ages of bighorn sheep.  In subsequent years, sporadic cases of pneumonia in adult bighorn sheep sometimes occur, but more importantly, lambs continue to suffer disease, resulting in low recruitment and stagnant population growth.  The only western state that has never experienced major bighorn pneumonia die off is New Mexico.

Reduced to a fraction of their former numbers, Fish and Game agencies around the West sought to re-establish wild sheep In places where they were extirpated. Despite these efforts wild sheep populations still the only number about 10% of their former numbers.

The biggest barrier to bighorn recovery today is due to the presence of domestic sheep. Bighorns do not occupy more of their former habitat is largely due to the fear that the wild sheep will contract pneumonia from their domestic cousins and die out.

In many states, suitable habitat remains unoccupied by wild bighorn sheep because of the close proximity of domestic sheep. For example, the Centennial Mountains on the Idaho-Montana border once harbored large herds of wild bighorns, but due to the presence of domestic animals at the Sheep Experimental Station, neither Idaho or Montana are willing to reintroduce bighorn sheep.

Worse for the wild bighorns, there is growing tendency to kill wild bighorn sheep as a precautionary measure to preclude the possible transmission of disease from domestic animals.

For example, New Mexico is currently killing 10% of the bighorn sheep in the Rio Grande Gorge within the Rio Del Norte National Monument as a preventative measure to reduce the chances of pneumonia transmission from domestic animals. As many as 48 sheep are scheduled to be shot in coming weeks by hunters in an effort to reduce the bighorn population. This is partially in response to the presence of domestic sheep grazing on BLM near the Gorge.

The idea that we kill the public’s wildlife to preserve grazing privileges of private ranchers using public lands for their private profit demonstrates a misguided priority. Instead of killing wild sheep, we ought to be removing domestic sheep grazing on public lands.

Both Western Watersheds Project and WildEarth Guardians have protested this killing.

In another example, in Montana’s Gravelly Range ranchers are permitted to shoot bighorns if they wander too close to domestic herds.

This raises a legitimate question. Why are wild bighorn sheep being killed on public lands while we give private livestock priority on these lands? A far more reasonable response would be to remove the private livestock wherever there is the slightest chance of wild and domestic sheep intermixing.

Grazing on public lands is a privilege, not a right. It can be revoked at any time and should be when public resources like bighorn sheep are put in jeopardy by the private livestock.

Due to the inaction of some federal agencies, we find that domestic sheep are permitted to continue grazing public lands even though they are aware of the presence of wild bighorns nearby.  The only way we can restore bighorn sheep to their former habitats and ensure their survival is by removing domestic sheep from any public lands within reach of the wild ones. Shooting wild sheep to “save them” is unacceptable.


  1. Sandra McGee Avatar
    Sandra McGee

    Great article George. I do love your articles. I learn so much form them.
    Time & time again I read about how man needs to kill the native wildlife in our country. With disastorous results.
    Mother Nature has always taken care of itself. I don’t understand why it’s so hard to come to grips with that.??
    Wildlife should always come first before domestic sheep, cattle. Science is a given. But, as we have found out @ least 35% of this country do not believe in sound based science. I fear for the wildlife all around the world –
    man has decimated so much of Mother Earth. I often get very depressed thinking about what has & will happen to the wildlife of the world. I know there are good folks out there who do care. I have met them. I just wish the killing would stop.
    Thank You George for educating me.

  2. James Bailey Avatar

    New Mexico has not been immune from bighorn disease dieoffs. At least, there were dieoffs in the San Andres Range and in the La Tier Wilderness. – With respect to bighorn habitat on public lands, agencies need to provide habitat in the interior of their lands, distant from boundaries where domestic sheep tend to occur. That is possible in the MT Gravelly Range. In contrast, the Forest Service and MT FWP are trying to maintain small, controlled bighorn herds on the peripheries of the Forest, with constant management expenses. The small population strategy has not worked for long, anywhere.

  3. Phil Maker Avatar
    Phil Maker

    Tribes need to pressure land management agencies to restrict/remove domestic sheep in promoting their treaty rights. The Nez Perce Tribe did great things for the bighorn along the lower Salmon River near Riggins. The Wild Sheep Federation and other pro-wildlife organizations should partner with Tribes to push this agenda.

  4. Sandra McGee Avatar
    Sandra McGee

    I agree with Phil

  5. John O'Connor Avatar
    John O’Connor

    Right on!!I need more of data like this to get domestic sheep removed from steens mountain here in s.e. oregon! Good on you George!

  6. Aj Avatar

    George, I agree agree agree!!


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George Wuerthner