Does the National Environmental Policy Act (NEPA) require a federal agency to analyze the environmental effects of separate upstream and downstream projects that are foreseeable but distinct from the project currently under review? Specifically, must the U.S. Surface Transportation Board evaluate the impacts of oil drilling and refining when approving a railroad line designed to transport crude oil? Furthermore, what level of judicial deference should courts apply when reviewing an agency's determination of the scope and detail of an environmental impact statement (EIS)?

• The Board prepared a comprehensive EIS exceeding 3,600 pages that analyzed the direct effects of the railroad line.
• Upstream drilling and downstream refining are separate, independent projects regulated by other agencies, not the Board.
• NEPA's textual focus is on the "proposed action" itself, and requiring analysis of attenuated third-party projects exceeds the statute's procedural purpose.
• The D.C. Circuit failed to apply the required judicial deference to the agency's factual determination regarding which details were relevant for inclusion in the EIS.

• The Board failed to take a "hard look" at all environmental impacts, including those that are reasonably foreseeable.
• Increased oil drilling in the Uinta Basin and increased refining on the Gulf Coast are direct consequences of the railway's construction.
• The EIS is deficient because it noted but did not fully analyze these significant upstream and downstream effects.
• The Board's statutory obligation to consider "public convenience and necessity" encompasses reasonably foreseeable environmental harms, including those resulting from increased oil production.

• The Court held that the D.C. Circuit failed to afford the Board substantial judicial deference and incorrectly interpreted NEPA to require consideration of separate upstream and downstream projects.
• NEPA is a "purely procedural statute" that prescribes process rather than mandating results, as established in *Robertson v. Methow Valley Citizens Council*.
• Courts must apply the Administrative Procedure Act's arbitrary-and-capricious standard, confirming only that an agency action was reasonable and reasonably explained (*Motor Vehicle Mfrs. Assn. of United States, Inc. v. State Farm Mut. Automobile Ins. Co.*).
• While the meaning of "detailed" in 42 U. S. C. § 4332(2)(C) is a legal question (*Loper Bright Enterprises v. Raimondo*), the specific details included in an EIS are factual determinations for the agency.
• Agencies must be granted broad latitude to draw a "manageable line" regarding indirect effects, and courts should not micromanage these choices (*Department of Transportation v. Public Citizen*; *Metropolitan Edison Co. v. People Against Nuclear Energy*).
• NEPA's textual focus is the "proposed action"—the project at hand—not separate projects that may be initiated as a result of the current project (42 U. S. C. § 4332(2)(C)).
• An agency is not a legally relevant "cause" of an effect if it has no ability to prevent that effect due to limited statutory authority (*Public Citizen*).
• The Board's EIS complied with NEPA because the railroad line and future oil development are separate, independent projects over which the Board possesses no regulatory control.