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Yellowstone National Park’s 5,000-strong herd of bison is one of its biggest draws for visitors—but now, Montana is suing the park over it.
A plan the NPS adopted this summer would allow the herd to grow by another 1,000 bison, which was its size in 2022 when park officials began drafting a new management plan. The park’s biologists claim that the park can support even more bison than the plan allows, while the state’s governor and many local ranchers worry that the growth of the bison herd could lead to the transfer of a reproductive disease called brucellosis from bison to cattle.
The bison herd size has been a long-time topic of debate amongst both park officials and locals.
While a study in Texas showed that bison are capable of transmitting the disease to cattle, transmission between the two species has never been documented.
The lawsuit also alleges that the park violated federal law by failing to include the state in talks surrounding the plan’s development. Montana Gov. Greg Gianforte said, “The National Park Service has repeatedly and consistently failed to engage with the State in a meaningful and transparent manner as required by law throughout the planning process.” He added, “NPS has not given us a fair shake and has ignored concerns raised by the State. We will always defend our state from federal overreach.”
Montana’s Director of the Fish, Wildlife and Parks Department, Christy Clark said, “Bison represent a complex and contentious issue with both livestock producers and wildlife advocates….We had hoped for and asked for a better and more transparent process in developing this EIS. Those requests were ignored.”
In a letter to Gianforte, Yellowstone National Park’s Superintendent, Cam Sholly, wrote that the governor’s allegations are untrue.
“Your recent letter called our offer to meet with you again ‘disingenuous,’ which is unfortunate. You’ve had multiple visits from me, senior DOI leadership, and Yellowstone’s wildlife team, at your request.”
Meanwhile, the Wind River Indian Reservations manager of the bison herd is looking forward to the growth, since it may allow the reservation to boost its bison numbers as well. Jason Baldes currently oversees 120 bison, 15 of which came from Yellowstone’s herd. In fact, Baldes was hoping the herd size would increase to 7,000.
“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,” Baldes told Wyoming Public Media. Gianforte hopes to limit the herd to 3,000 animals, halving current allowances.
“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,” said Baldes.
From 2025