After decades, bison are finally allowed to roam year round outside of Yellowstone National Park.
This story is featured in Montana Outdoors March-April 2017 issue
On a sunny, cloudless day in June 2016, the sidewalks of West Yellowstone are packed with tourists. A line of cars and SUVs stretches for more than a mile from Yellowstone National Park’s western entrance back through the small town.
Most of the visitors inching along the road hope they will soon see wildlife—bears, moose, or, most exciting for many, bison. They don’t realize that, just a few miles north, outside of the park, dozens of the brown, shaggy brutes are bedded down in lodgepole pines on either side of the road. Dozens more lounge in family groups on grassy Horse Butte, a peninsula jutting into Hegben Lake just a few miles west.
That bison now range outside the park in late spring is a remarkable conservation milestone. A decision by Montana Governor Steve Bullock in early 2016 allowed hundreds of the large mammals to live beyond the park’s western boundaries year round for the first time in decades. The decision broke a longstanding impasse between wildlife advocates who want to see bison roam outside Yellowstone and livestock interests concerned the animals will spread disease to cattle.
To fully appreciate the significance of free-ranging bison here requires understanding the long and complex relationships linking the large animals, the nation’s first national park, the people who visit Yellowstone, and those living and ranching near its borders.
From countless to controversial
Bison once covered the North American plains from Canada to Mexico in numbers ranging from 30 to 60 million. Also known as buffalo, the 1,000- to 2,000-pound grazers were vital to Native American tribes. “Bison were at the very heart of our traditional way of life,” says Tom McDonald, director of the Confederated Salish and Kootenai Tribes’ Fish, Wildlife, Recreation, and Conservation Program. “They provided clothing, shelter, food, and tools, and were central to our spirituality.”
But market hunting and U.S. Army efforts to weaken Indian resistance in the late 1800s wiped out herds to a point of near extinction. Bison numbers plummeted to fewer than 1,000 by the turn of the 20th century. Only 30 remained in Yellowstone National Park.
America’s budding conservation movement galvanized around the plight of the animal, which was seen as an icon of the wild American West. Groups like the recently formed Boone and Crockett Club and American Bison Society pressured Congress to protect herds in the newly established Yellowstone National Park and other public wildlife refuges. The Lacey Act of 1900 put teeth into the fight against poaching and charged the Army with guarding the small group of surviving Yellowstone bison.
No one knew how to manage the wild ungulates, so early efforts mimicked livestock practices. Calves were bottle fed, and the animals were given hay in winter and kept in corrals. Managers also added to the tiny Yellowstone population, such as by moving 18 cow bison from the Pablo-Allard herd north of Missoula to the park.
Lacking natural predators and protected from hunting, Yellowstone’s bison population quickly increased by the hundreds. Then, in 1917, came the first discovery of brucellosis in the herd. The bison likely contracted the disease, which can cause both cows and bison to abort their fetuses, by mixing with cattle. This discovery set the stage for nearly a century of intense conflict and negotiation over bison management, often pitting federal and state livestock, wildlife, and park agencies against one another.
Starting in 1967, park officials began a policy of “natural regulation,” which allowed bison to migrate out of the park in winter when deep snows covered grass in the high-elevation park. By the 1980s, bison were regularly crossing park boundaries to lower-elevation areas around Gardiner, at Yellowstone’s northwestern entrance, and West Yellowstone.
Another factor driving the animals out of the park was population size. “Bison didn’t want to leave Yellowstone until their numbers hit 2,000 and grew too large for the park to sustain,” says Pat Povah, who owns a cattle ranch near West Yellowstone.
By the 1990s, with brucellosis essentially eradicated in cattle, the U.S. Department of Agriculture designated livestock in all but a few states “brucellosis free.” Yet elk and bison that carried the disease—more than half of Yellowstone’s bison population tested positive—conceivably could still infect nearby cattle. Ranchers maintained that bison posed a great risk to livestock in the so-called Designated Surveillance Area around the park. “Concerns over the spread of this disease have required testing of cattle before sale or transport out of the surveillance area,” says Marty Zaluski, state veterinarian with the Montana Department of Livestock.
Two often-conflicting goals
Concerned about the risk of brucellosis transmission, Montana sued the park in the 1990s to keep bison out of the state. A court-mediated settlement reached in 2000, called the Interagency Bison Management Plan (IBMP), created a blueprint for managing the animals. The park, seven Montana and federal agencies, and several Indian tribes now carry out the plan, which has two ambitious, though often-conflicting, goals: 1) maintain a wild, free-ranging (including outside the park boundaries) population of bison, and 2) reduce the risk of brucellosis transmission to nearby cattle to maintain Montana’s brucellosis-free status.
To reduce the chances of disease transmission, the plan establishes tolerance zones in Montana where bison and cattle are separated by fencing or distance. The plan also sets a target population of 3,000 bison in the park to prevent overcrowding and habitat degradation.
To rein in the range and population of the Yellowstone herd, which some years grows to more than 5,000, agencies working under the plan have hazed the animals back into the park using horseback riders, four-wheelers, and, in special cases, helicopters. Managers also use regulated hunting by the public and tribal members, and they cull the herd by sending bison to slaughter and donating the meat to Indian tribes.
The plan has its detractors. Bison advocates such as the Buffalo Field Campaign and some Indian tribes denounce hazing and culling, arguing that the practices unnecessarily harass and kill bison. Some ranchers still contend that the plan doesn’t do enough to protect their property from bison damage or their livestock from disease.
Still, no brucellosis transmission from bison to cattle has occurred since the plan was adopted. That means one IBMP goal is being reached. Yet the other—allowing some bison to range free outside the park—has remained elusive until recently.
Tolerance to the north and west
Several years after the bison plan was first put in place, the multidisciplinary team that wrote it started looking more critically at hazing and culling. Though both practices keep cattle safe, the work is expensive and casts the entire bison management operation in an unfavorable light. A possible solution to the conundrum came in the early 2000s, when scientists learned that bull bison present almost no risk of brucellosis transmission. Suddenly it seemed feasible to consider allowing males outside the park.
Inspired by the new science, in 2010 the Citizens Working Group on Yellowstone Bison, a diverse collection of ranchers, tribal members, and bison advocates, recommended letting bison live year round in areas of Montana next to Yellowstone. IBMP partners agreed to let bulls roam on public land north of the park, from Gardiner Basin as far north as Yankee Jim Canyon, about 11 miles from the boundary. As part of the agreement, fences and cattle guards were installed to prevent the bison from roaming farther north into Paradise Valley, home to several large cattle ranches. New fences in Gardiner would protect trees, backyards, and gardens from the free-roaming animals. Bison ranging outside the new tolerance areas would be hazed back inside or lethally removed.
Since 2011, bison leaving the northern park boundary in winter have been, for the most part, left alone. No brucellosis transmission to cattle has occurred.
Heartened by the success of the Gardiner expansion and urged on by the citizen’s working group, the IBMP partners next decided to look at allowing bison expansion outside the park’s western border. Bison cows were leaving the park’s snow-crusted meadows in early spring in search of grass, which they found on the south-facing slopes of Horse Butte in Hebgen basin. “That’s really important for them in late winter and early spring, when they’re in late pregnancy and carrying calves. They need that extra nutrition,” says Rick Wallen, the park’s bison ecologist. What’s more, cattle no longer grazed on Horse Butte, and few grazing allotments remained in the larger area. Yet at the time, the IBMP still called for hazing bison that crossed the western boundary back into the park by May 15. Was that arbitrary deadline still necessary?
In 2015, after FWP and the Montana Department of Livestock were unable to agree whether hazing needed to continue, Governor Steve Bullock issued a decision to allow bison in a limited area on Yellowstone’s west perimeter, including Horse Butte and the Taylor Fork drainage. To allay ranchers’ fears that bison would continue expanding west, Bullock ordered that the animals not be allowed beyond prescribed boundaries, varying by season. Culling, hazing, and hunting would still be options to keep the bison within the new expanded range.
Adjusting to change
In spring of 2016, following Bullock’s decision, 300 to 400 bison moved to Horse Butte and public lands to the north and grazed there for a few months before most returned to the park during summer. “The governor’s decision saves money by not having to conduct large-scale hazing operations in the Hebgen Basin, and lets bison be bison while not putting livestock at risk,” says Sam Sheppard, FWP regional supervisor in Bozeman. Bison can now live year round outside the park, north and west, on more than 400 square miles of public land.
Supporters of the new bison policy include the Greater Yellowstone Coalition. “Bison are wildlife and should be treated as such. I see this decision as a move in that direction,” says Shana Dunkley, of the organization’s Wildlife Program. McDonald, of the Confederated Salish and Kootenai Tribes, welcomes the governor’s decision. “This is restoring our traditional relationship with bison,” he says.
Not everyone is on board. Povah, the rancher, opposes the new policy, fearing it will damage the land and vegetation. “When bison come out of the park in early spring, this ground is extremely fragile. If you let bison or cattle trample it, it won’t recover in our lifetime,” he says.
The governor’s decision doesn’t end the need for periodic lethal removal to keep Yellowstone bison numbers at a healthy level. In fact, in January 2017, the IBMP partners announced plans to cull the population, which had grown to a near-record level of 5,600 due to mild weather the previous winter, by up to 1,300.
As with building tolerance for population management, increasing the acceptance of bison outside the park will take time. “We need to take an incremental approach to allow people living here to adjust and learn how to live with bison,” Dunkley says. Key to building bison tolerance will be for the IBMP partners to continue solving problems such as bison knocking down fences and posing a disease risk. “Most people who love bison don’t have to live with them,” Povah says.
People will continue to disagree about Yellowstone’s bison and the animals’ expansion outside park boundaries. Some will demand a return to hazing and greater population reduction, while others will insist on further range expansion and an end to culling. “This issue is far from over,” Sheppard says. “But for now, it seems like we’ve reached a fair and scientifically sound compromise that both the bison and the livestock community can live with.”
For their part, the bison at and around Horse Butte appear content just to graze and loaf. They seem oblivious to the cars off in the distance, filled with people yearning to spot wildlife that, if they only knew, can now be seen in some places outside of the park, too.
Andrea Jones is the Regional Information and Education Program manager in Bozeman.
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