Kleppe v. Sierra Club, 427 U.S. 390 (1976) (U.S. Supreme Court)
Kleppe v. Sierra Club is a foundational National Environmental Policy Act (NEPA) decision that defines the trigger for environmental review at the broad, programmatic level.
Under NEPA, must the federal government prepare a single, comprehensive (programmatic) EIS for anticipated coal development across the Northern Great Plains absent a concrete, proposed federal regional development plan, or can environmental review proceed through project-specific EISs unless and until related proposals are pending concurrently and require integrated analysis?
NEPA requires an environmental impact statement for proposals for major Federal actions significantly affecting the quality of the human environment. The obligation to prepare an EIS is tied to the existence of a concrete proposal, not to abstract plans or general policy considerations. Agencies must consider in a single EIS related proposals that are sufficiently connected or concurrently pending and that have cumulative or synergistic environmental impacts. The determination of whether a proposal exists and the appropriate scope of an EIS are committed, in the first instance, to the responsible agency, subject to judicial review under the Administrative Procedure Act's arbitrary-and-capricious standard and guided by the Council on Environmental Quality (CEQ) guidelines.
No programmatic, region-wide EIS was required because the federal government had not proposed a comprehensive regional development plan for the Northern Great Plains. NEPA does not compel the preparation of a regional EIS based solely on anticipated cumulative development. However, when multiple related proposals with cumulative or synergistic impacts are pending concurrently, agencies must consider them together in an appropriate EIS.
Kleppe is the leading case on programmatic EISs. It clarifies that (1) NEPA's EIS duty attaches to concrete proposals for major federal action; (2) absent a formal proposal, courts should not compel a speculative, region-wide EIS; and (3) agencies must still address cumulative and synergistic impacts where multiple related proposals are pending together. The case also reinforces deference to agency judgments about the scope and timing of NEPA review, grounded in CEQ guidance and policed by arbitrary-and-capricious review. Practically, it delineates the boundary between premature 'big-picture' review and improper segmentation, shaping how agencies structure environmental analyses and how litigants frame NEPA challenges.