The state of Montana in mid-September requested to dismiss its lawsuit over bison management in Yellowstone National Park.
In December 2024, Montana filed suit against the National Park Service’s (NPS) 2024 Interagency Bison Management Plan. The bison plan allows for about 5,000 bison in Yellowstone National Park and opportunities for Tribes to restore bison to Tribal lands.
The state’s lawsuit was later consolidated with a similar case from two conservation groups, Alliance for the Wild Rockies and Council on Fish and Wildlife. In early 2025, environmental groups and regional Tribes intervened in the case in defense of NPS.
Montana argued that NPS failed to consult the state on its bison management plan and potential disease transmission. The conservation groups claimed the plan failed to use the best scientific analysis for bison management.
“Given the way NPS has ignored feedback from Montana, we have major concerns about potential threats to animal health from the possible spread of brucellosis,” said Mike Honeycutt, director of the Montana Department of Livestock, at the time of the suit’s filing.
Lawsuit dismissal
In a Sept. 14 filing in the U.S. District Court for the District of Montana, the state of Montana and the Department of Interior filed a joint motion to dismiss the case without prejudice.
“With the Federal Defendants’ initiation and subsequent pursuit of a (Supplemental Environmental Impact Statement, SEIS) that identifies new alternatives and provides additional analysis, there is potential that Montana’s claims will be addressed, if not resolved, by that process,” the state’s motion read. “As such, dismissal without prejudice allows parties to focus resources on that process.”
The Alliance for the Wild Rockies and Council on Fish and Wildlife were not included in the request for dismissal.
Intervenor groups applauded the state’s move to dismiss the lawsuit.
“Now that the state of Montana has moved to dismiss its baseless lawsuit, we urge Yellowstone to stand by its progress on bison conservation,” said Jenny Harbine, managing attorney for Earthjustice’s Northern Rockies Office. “When the Park Service releases its draft SEIS in the coming months, the public will have yet another opportunity to demand continued protections for our national mammal.”
Earthjustice represents the Fort Peck Assiniboine and Sioux Tribes, National Parks Conservation Association, Defenders of Wildlife, the Greater Yellowstone Coalition, and Park County Environmental Council in the intervention.
Lawsuit background
In late April, NPS announced its intent to prepare an SEIS to update the analysis used in the plan.
“Seasonal bison migration out of the park has become less predictable in timing and duration,” the notice read. “This change affects the reliability of management assumptions that informed the 2024 analysis, warranting supplemental review.”
The agency also noted that its review will determine whether additional analysis of any of the issues raised in the lawsuit is appropriate.
The Department of the Interior in May requested a stay on the lawsuit pending NPS’ SEIS, which a federal judge denied on behalf of the plaintiff conservation groups’ claims.
“A stay would fail to simplify the proof or questions of law at issue in this case,” Morris wrote in his order. “NPS’s focus remains independent from Alliance Plaintiffs’ claims in this matter.” — Anna Miller Fortozo, WLJ managing editor
