Battle for Bighorns

Conservationists are struggling to protect bighorn sheep on public lands from disease-carrying livestock

  • Rocky Barker
  • Jul 15, 2011

A SEVEN-YEAR-OLD bighorn ram, radio collared as part of a study by biologists of the Nez Perce tribe, stood on a bluff overlooking rancher Mick Carlson’s corrals one day in May 2009. His coat gray with age, the ram was no stranger to Carlson’s ranch, which lies in the Salmon River Canyon east of Riggins, Idaho, on the edge of the Payette National Forest and a stretch of Bureau of Land Management (BLM) grassland. The radio collar showed that the ram had visited Carlson’s ranch frequently. He was a member of a native bighorn population that roams more than 25 miles up and down the Salmon River Canyon through the Frank Church-River of No Return Wilderness Area.

The ram didn’t cut the majestic figure that has made Rocky Mountain bighorn sheep iconic in the American West; he was coughing and sneezing from pneumonia. This very disease has killed more than 1,000 wild sheep in recent years in more than a dozen herds across the West. It is a disease that can be passed to bighorns from their domestic cousins and that has been implicated in a developing crisis: After 70 years of growth, bighorn numbers began dropping steadily in the 1980s. Rocky Mountain bighorn sheep populations in the United States, Alberta and British Columbia were estimated in 1998, the most-recent date for reliable figures, at fewer than 30,000 animals, less than half of their number a few years earlier.

How this decline is progressing at various local sites in the West can be seen in Salmon River Canyon country. The old ram’s herd, which has lived among domestic sheep for much of the past century, has dropped 76 percent since the 1980s to only about 100 animals. This decline is unacceptable to several conservation groups and to the Nez Perce Indians, who have treaty rights to bighorns in the Hells and Salmon River Canyons. The wild sheep have long been important culturally to tribal members, who historically turned the animals’ curved horns into bows and their thin, tough hides into clothing. “How can the Nez Perce people maintain our culture if we do not have enough bighorn sheep to pass along the skills and knowledge of our forefathers to our sons and daughters?” asked Brooklyn Baptiste, vice-chairman of the Nez Perce.

The issue started coming to a head in 2007 in Payette National Forest, where disease was killing bighorns. The U.S. Forest Service, moving toward a collision with the Idaho Woolgrowers Association and the industry it represents, determined that under its planning regulations, the bighorns took precedence over domestic sheep that ranchers grazed on leased forest lands. “The science is clear that domestic and wild sheep can’t live together,” says Kevin Hurley, conservation director for the Wild Sheep Foundation, a group of sportsmen who have spent millions of dollars to restore bighorns.

The Nez Perce and NWF sought to address the issue by helping ranchers find new places to put their sheep, but 72-year-old Carlson and other ranchers who leased grassland in Payette refused. “It soon became apparent to us that many sheep operators would rather fight than win,” recalls Steve Torbit, executive director of NWF’s Rocky Mountain Regional Center in Boulder, Colorado.

That intransigence triggered a series of legal battles. The Western Watersheds Project, the Hells Canyon Preservation Council and the Wilderness Society sued to require the Forest Service to enforce its policy of protecting bighorn habitat. In 2008, U.S. District Judge B. Lynn Winmill ruled that ranchers were barred from grazing sheep in the Payette.

In April 2009 the Idaho Woolgrowers Association responded by pressing the state legislature to require the Idaho Department of Fish and Game to kill bighorns when they came in contact with domestic sheep anywhere in the state. This proposal was a major threat to bighorns. Although federal land agencies such as the Forest Service and BLM have jurisdiction over wildlife habitat on public land, states usually have control over wildlife within their borders.

Changing Plans

Meanwhile, Suzanne Rainville, supervisor of Payette National Forest, was completing a rewrite of the forest management plan in response to appeals by the Nez Perce and by conservation groups that said the plan failed to protect bighorns adequately. Winmill’s court decision strengthened the tribe’s case and led Rainville to phase out domestic sheep grazing on 70,000 acres of bighorn habitat. When she released her revised plan in 2010, nine ranching and wildlife groups, including the Nez Perce, appealed the plan to the regional forester. Ranchers wanted the new plan overturned, while conservation groups and the tribe wanted it implemented sooner than the Forest Service required. Regional Forester Harv Forsgren upheld Rainville’s alternative, and the woolgrowers appealed his decision to the chief of the Forest Service, Tom Tidwell. His approval of the plan last April sets the stage for further litigation.

“Tidwell’s decision is one of the most rigorously scientific decisions I have ever encountered by the Forest Service in my career,” Torbit says. “Now it’s time for the livestock producers and wildlife folks to roll up their sleeves and work together to find areas suitable for domestic sheep.”

Torbit and other bighorn advocates hope they can persuade western sheep ranchers and federal officials to develop a strategy that will allow bighorn sheep populations to expand through conservation and further reintroductions across the West. Colorado—which harbors nearly 7,000 bighorns, among the largest bighorn populations in the West—is seeking to stop a decade-long decline by limiting the spread of disease and using reintroductions. A critical area, Torbit said, is the San Juan Mountains in southwest Colorado, where they need the support of the domestic sheep industry to succeed. Hurley agrees: “We have to turn over every stone to find alternative arrangements for ranchers, or we’re going to continue to have conflict.”

Disease Strikes

More than 2 million bighorn sheep roamed the American West in the 1800s, experts estimate. By 1906, uncontrolled hunting and the westward push of civilization had reduced bighorn populations to 15,000. More recently, biologists have connected the demise of bighorns to their contact with the millions of disease-carrying domestic sheep that grazed in the Rocky Mountains by the end of the nineteenth century.

With the support of hunters, state wildlife agencies restricted hunting and, in the 1950s, started reintroductions that restored bighorn numbers to as many as 70,000 animals across the West. But as bighorn populations increased, they again came into contact with domestic sheep and their diseases. Wildlife managers blamed the decline on the transmission of Pasteurella bacteria, which cause pneumonia in both domestic and wild sheep, though domestic animals are more resistant to the disease.

Although scientists don’t know how the disease is transmitted, what factors contribute to transmission and whether transmission of other bacteria, even among wild sheep alone, contributes to the bighorn die-offs, mounting evidence suggests that domestic sheep are a major vector. A 2008 study by Colorado Division of Wildlife scientists showed that a single domestic sheep that wandered onto bighorn winter range caused a die-off of more than 86 bighorns from 1997 to 2000.

The old, sick ram that appeared on BLM land in Carlson’s area helped convince officials to shut down Carlson’s BLM grazing lease shortly after the Payette National Forest closure. He felt forced to call it quits. “Right now if you are a rancher and a bighorn shows up, you’re done,” says Carlson’s attorney, William Myers of Boise. Carlson might have been able to move his sheep operation but, he alleges, doing so would have been costly and would have forced him to move out of an area he loves. Nez Perce tribal wildlife manager Keith Lawrence says that in restricted habitats such as the Salmon River Canyon and Hells Canyon, the best deal for ranchers is either to find new range, as conservationists have urged, or to have the government or other groups buy them out. “If the bighorns recover as we hope they do, they are going to expand,” he says.

Seeking Solutions

The U.S. domestic sheep industry has been on a steady decline for decades, dropping from a peak of 56 million head in 1942 to 6.2 million in 2007. Lamb prices are up now, however, and the industry is poised to grow, says Margaret Soulen Hinson, president of the American Sheep Industry Association. Hinson’s family runs 10,000 sheep from a base ranch near Weiser, Idaho. Some of their range in the Payette is just over the mountain from Carlson’s ranch and the Salmon River bighorns.

Hinson worries that the Payette decision will become the basis for federal land policy throughout the West, where 80 percent of domestic sheep range lies and where nearly 4 million sheep graze. In her view, “it would be devastating to the domestic sheep industry,” she says.

NWF’s Torbit doesn’t want to see the sheep industry brought down. “I don’t want to start a new range war, because it’s not good for anybody, and it’s certainly not good for wildlife,” he says. He favors a collaborative process that brings ranchers, sportsmen, tribes and conservationists together to protect the range and wildlife but still allows ranchers to thrive.

Hinson says a better understanding of all the stressors that bighorn face and more research on sheep diseases are critical to any collaborative effort. She knows that separation is critical, but like many sheep ranchers she’s skeptical that 100 percent separation is possible without putting ranchers out of business. One bright spot in this dilemma is some promising research on a vaccine at Washington State University.

When Idaho Fish and Game biologists finally captured and examined Carlson’s wild ram, they found that the bacteria in the bighorn’s system were not the same as those documented in Carlson’s domestic sheep. No other bighorn deaths were reported. The results that biologists hoped would settle the issue gave neither side solace. Even though it’s clear that domestics pass disease to wild bighorn, it’s not clear that contact always results in death. In the end, bighorns won the Idaho fight, but the animosity that came from it will make it harder to build common ground.

The Wild Sheep Foundation’s Hurley, who managed bighorn sheep for the Wyoming Game and Fish Department for 30 years, is hopeful a west-wide solution is possible. He supports a kind of zoning that would give bighorns primacy in some areas and domestic sheep in others. For example, in Wyoming’s Shoshone National Forest, next to Yellowstone, conservation groups bought out domestic sheep ranchers to protect the forest’s 4,000 bighorns. In other areas, including Bighorn National Forest east of Shoshone, where bighorn numbers are small, domestic sheep take priority.

For Hurley, who found success for bighorns and ranchers in Wyoming, the message is simple: “If you believe in compromise and conservation, both sides have to give up something.”

Rocky Barker is the environmental writer for the Idaho Statesman. He was awarded NWF’s Conservation Achievement Award for communications in 1998.

NWF in Action

Seeking Bigger Bighorn Numbers

NWF assisted with the funding for the Nez Perce bighorn monitoring program on the Salmon River. NWF is working with tribes and groups in Idaho, Washington and Oregon to persuade the U.S. Forest Service to consider alternate range for ranchers pushed off of the Payette National Forest. The Idaho Wildlife Federation, an NWF affiliate, also is working with partners such as the Nez Perce to actively lead efforts to safeguard bighorns and their habitat on public lands throughout the state (visit  

Meanwhile, Federation regional staff in Colorado and Montana are working with sheepgrowers and other livestock interests throughout the West to reduce conflicts between domestic stock and wildlife, including grizzly bears and bison as well as bighorn sheep. Through its Adopt a Wildlife Acre program, NWF has succeeded in retiring more than 550,000 acres of grazing-lease allotments on federal public lands near Yellowstone National Park. In a recent victory, NWF persuaded a rancher near Gardiner, Montana, to stop grazing cattle on 75,000 acres north of the park, offering new habitat to bison that leave Yellowstone in winter. While the program currently does not yet specifically include bighorn sheep habitat, NWF is looking at potential grazing allotments that, if retired, could benefit the animals. For more information, visit NWF's Adopt a Wildlife Acre program.


In the fiscal year 2012 Interior and Environment Appropriations bill recently passed, the U.S. House of Representatives Appropriations Committee slashed funding for the Department of the Interior. How will the bill affect bighorn sheep?

A rider in Section 442 of the bill, introduced by Idaho Representative Mike Simpson, strips all federal land management agencies of their ability to require livestock ranchers operating on public lands to move domestic sheep in order to prevent the transmission of a deadly pneumonia to wild bighorns. This provision apparently was drafted in response to the recent decision by the Payette National Forest (see article, above) to create buffer zones between domestic and bighorn sheep. The Payette decision is based on years of analysis and exhaustive scientific study of bighorn and domestic sheep movements and disease transmission patterns. Although it did not go as far as bighorn sheep advocates favored, the decision represents a reasoned and balanced attempt to minimize disruption to livestock producers while giving bighorn sheep a chance at long-term survival and recovery. 

Section 442 also would prevent any reduction in livestock numbers or change in distribution in order to manage bighorn sheep, no matter how small the change in livestock operations or how urgent the need to avoid extirpation of bighorn populations by disease outbreaks. This is an indefensible exclusion from existing law and scientific consensus for one small economic interest. It shuts out not only the Forest Service’s own normal decision-making process but also the voices of Indian tribes, state wildlife agencies, sportsmen, and wildlife advocates. Section 442 would appear to prevent even movement of livestock as an emergency action to manage bighorn–domestic sheep contact and prevent fatal episodes of pneumonia in the bighorns. This could increase the likelihood that bighorn populations will decline to the level where listing under the Endangered Species Act would be warranted.

Another rider introduced by Simpson in Section 120 of the House bill exempts domestic sheep trailing across federally managed lands from any National Environmental Policy Act (NEPA) review of trailing of livestock across public land. NEPA review of trailing decisions has been very important to efforts to reduce bighorn–domestic sheep contact and disease transmission. It is not appropriate for funding authorizations to compromise legislation already enacted.


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