Yellowstone National Park’s new bison plan allows the herd to grow by about 1,000 more than it's been in the past decade. The ten year average size of the herd has been around 5,000 animals.
Park biologists say park land can handle even more bison. But it’s limited by the amount of winter habitat outside the park in the state of Montana.
The state’s governor has threatened to constrict how far bison can roam there and potentially a lawsuit.
Meanwhile, the manager of a bison herd on the Wind River Indian Reservation hopes the park will grow its herd, so he can grow his tribe’s, too.
Jason Baldes manages about 120 bison for the Eastern Shoshone tribe. The cupholders in his side by side vehicle are filled with clumps of bison hair.
“All these buffalo are losing their winter coat right now, so they are all sloughing off,” he said on a windy day in early June as he pointed to about a dozen male bison munching on grass.
Fifteen of the tribe’s bison came from Yellowstone National Park’s herd, 10 of which were received earlier this year.
And Baldes is hoping for more Yellowstone bison under the park’s recently signed bison management plan. The new plan replaced one from more than 20 years ago. It prioritizes transferring bison to tribes, along with tribal hunts, to keep the herd between 3,500 and 6,000 animals.
Baldes had hoped the park would up the herd to 7,000, which was one of the three options considered in the planning process.
But he said their choice of 6,000 is a good compromise. He said he’s glad the park made the decision based on scientific factors like habitat availability in the park and didn’t cave to political pressures.
“Buffalo have been subjected to the whims of the stockgrowers and the cattle industry forever since cattle arrived and so that status quo is something that needs to be challenged,” he said.
Since 2001, about 11,700 bison have been removed from the Yellowstone herd as part of an interagency agreement to maintain a free roaming bison population, while preventing conflicts and disease transmission. Each year, federal, state and tribal agencies meet to discuss how much to reduce the population by and with which methods.
More than half of the 11,700 have been sent to slaughter in a program where meats and hides are given to tribes. Tribal treaty and state hunts have removed more than 4,000. Around 600 have been placed in the bison conservation transfer program, which after quarantining, rehomes disease-free bison to tribes like the Eastern Shoshone.
But in recent years, the park has tried to move away from slaughtering so many animals. In 2023 it more than doubled its capacity to transfer bison to tribes and aims to operate the program at full capacity moving forward.
Chris Geremia is Yellowstone’s bison biologist. He said Yellowstone can easily handle 6,000 bison.
“There is plenty of grassland and plenty of habitat in this park for more bison than that, but the conflict with bison occurs in the wintertime. We have to take into account the amount of habitat that’s allowed for them by the state of Montana outside of the park,” he said.
According to the plan’s final environmental impact statement, there is enough forage in the park for 10,000 bison in the summer months and 6,500 during the winter, “although large variations in weather and grass production from year to year add complexity to this estimate.”
In the winter, sometimes bison migrate outside of park boundaries into two tolerance zones on 400 square miles of public lands in Montana located just outside the park’s North and West entrances. The livestock industry and Montana’s governor are worried that bison could give cattle a reproductive disease called brucellosis.
Gov. Greg Gianforte wants to limit the herd size to 3,000 animals. In letters responding to the plan, he threatened to sue and said the state might change the tolerance zones where bison are currently allowed.
The governor and the head of the Montana Department of Livestock declined to be interviewed for this story. In a statement, the governor’s office said they are reviewing the plan.
“The announced plan from the Biden administration is yet another insult to the state of Montana. It is not based in science, fails to incorporate any comments from our agency professionals, and reflects a total disregard for the rule-making process,” Sean Southard, Gianforte’s director of communications, wrote in an email.
Yellowstone Superintendent Cam Sholly said the park is keeping the herd at the same size it’s been for the past 10 to 15 years and that reducing it to 3,000 would require slaughtering a massive amount of bison each year. That’s not something the park wants to do.
“The question is why? Why would you change the tolerance zones? That’s the question for the state?... I don’t understand the logic. We haven’t had a brucellosis transmission between bison and cattle. We’ve successfully managed the interface even in a record migration year ‘22, ‘23. ”
Sholly’s talking about 2022 when the herd reached a record high of close to 6,000 animals. That winter, more than 1,000 were killed by tribal and state hunters outside the park.
In Wyoming, wildlife officials say increasing the Yellowstone herd will have minimal impacts. A Wyoming Game and Fish spokesperson said that’s because the bison they manage primarily migrate out of Grand Teton National Park.
Back at the Wind River Indian Reservation, Baldes pointed to a range unit recently converted from cattle grazing to bison habitat. It’ll increase bison habitat for his tribe’s herd by more than eight times.
“Everything south of the river is that 17,000 acre range unit, so we’re getting ready to begin construction on that fence line that’ll go around the 17,000 acres,” he said.
Fence construction starts this month. And there are plans to combine the Eastern Shoshone and Northern Arapaho bison herds, growing the total number of bison at Wind River to more than 200.
While Baldes is confident he’ll receive more Yellowstone bison from the transfer program, it’s not yet clear when or how many. He’s hopeful more bison in Yellowstone will eventually mean more bison here.
“My vision is thousands of buffalo on tens to hundreds of thousands of acres, restoring migration [corridors] and a real contribution to the Greater Yellowstone ecosystem, one of the few places on the whole planet where many of these species still exist that haven’t been systematically removed or eradicated,” he said.
For now, the park will manage for under 6,000 animals. More than a hundred are slated to be transferred to tribes each year.
