What the proposal said, and what the decision did

No figure from the proposal has been checked against the decision on this fight yet. What the record does hold is the issues ledger below.

The National Park Service is launching a supplemental environmental review to update its 2024 Yellowstone bison management plan because seasonal bison migration has become less predictable in timing and duration. The supplemental EIS will reassess management assumptions that no longer reliably reflect current bison movement patterns. This affects Yellowstone's bison herd, surrounding states and tribes involved in bison management, and adjacent public and private landowners who deal with bison leaving the park.

In the agency’s own words

The National Park Service (NPS) intends to prepare a Supplemental Environmental Impact Statement (SEIS) to update the analysis in the Yellowstone National Park Bison Management Plan Final Environmental Impact Statement (EIS), 2024. Seasonal bison migration out of the park has become less predictable in timing and duration. This change affects the reliability of management assumptions that informed the 2024 analysis, warranting supplemental review.

Federal Register 2026-08277 ↗

The groups on this fight

4 groups predicted likely to care in Idaho and Montana

Predicted likely to care is a guess from the group's sourced work in Idaho and Montana, with no link to this decision. Give straight to them; nothing routes through us.

• American Prairie

  Predicted likely to care · a guess

  American Prairie, Montana: Defending its own bison herd, formally protesting BLM's revocation of grazing permits on 63,000 public-land acres.

• Earthjustice

  Predicted likely to care · a guess

  Cabinet Mountains Wilderness, Montana: Counsel in the long-running litigation against the Rock Creek and Montanore mines proposed beneath the wilderness.

• Idaho Conservation League

  Predicted likely to care · a guess

  Craters of the Moon National Monument, Idaho: Mobilized Idahoans to file Interior Department comments defending Craters of the Moon during the 2017 national monument review, arguing shrinkage would damage the economies of Blaine, Butte, Minidoka, and Power counties.

• Western Watersheds Project

  Predicted likely to care · a guess

  Bruneau-Jarbidge Rivers, Idaho: Challenging BLM's grazing management across 1.4 million acres of the Jarbidge and Bruneau river canyonlands, where it won an injunction blocking ranchers from grazing beyond their permit limits.

Every group above is on STAND for Public Lands, with its court record, its filings and who backs it.

Who signs it

The notice names no signer PLAN could read. PLAN names a decision-maker only when the document names one.

The ground

The window has closed, so there’s no watch to set on it here.

The photograph on this page: Grizzly bear crossing sage flats, Greater Yellowstone. More Than Just Parks.

In court on this ground

3 court cases are over Yellowstone National Park, newest first.

• Docket closed · latest entry September 15, 2026

  State of Montana v. Haaland

  Latest entry we hold: “Brief/Response to Order re 146 Order on Motion to Dismiss, filed by Cottonwood Environmental Law Center.”

• Ruled · December 11, 2025

  Center for Biological Diversity v. U.S. Forest Service

  The court: “The South Plateau Project EA and Decision Notice are VACATED and REMANDED to the agency to address the identified deficiencies.”

• Ruled · April 5, 2021

  Crow Indian Tribe v. United States

  The court: “ORDER: Crow Indian Tribe's Motion 323 is DISMISSED with prejudice.”

Who holds the vote

PLAN’s record doesn’t tie a member of Congress to this fight yet. The scorecard grades the votes and bills that decide public lands; nothing joins a vote or a bill to this decision, so there’s no member to name here without guessing.