The National Park Service intends to prepare a Supplemental Environmental Impact Statement (SEIS) to update the analysis in the 2024 Yellowstone National Park Bison Management Plan Final EIS. Seasonal bison migration out of the park has become less predictable in timing and duration, affecting the reliability of management assumptions in the 2024 analysis. The SEIS will develop one or more new alternatives beyond those previously considered, including elements previously dismissed or not yet analyzed. The 2024 Final EIS is also subject to two lawsuits in the District of Montana, and NPS will evaluate whether additional analysis of issues raised in those cases belongs in the SEIS. Public scoping comments are due by May 29, 2026.12