One year ago, on May 29, 2025, the US Supreme Court issued its unanimous decision in Seven County Infrastructure Coalition v. Eagle County, which established a “course correction” to bring agency compliance and judicial review under the National Environmental Policy Act (NEPA) back in line with the statutory text.¹ The Court aimed to rein in practices by agencies and lower courts that over time had expanded the NEPA process beyond its statutory basis and to clarify that courts must afford substantial deference to agency decision-making in implementing this procedural statute.²

Federal courts have since applied Seven County consistently across a broad range of NEPA disputes. Based on a review of dozens of district and circuit court decisions applying Seven County, this alert provides a one-year retrospective, highlighting key trends and practical takeaways for entities navigating NEPA review. The emerging case law reflects a strong and consistent trend demonstrating that lower courts are embracing the Supreme Court’s directive to defer to agency judgments across nearly every dimension of the NEPA process.

At the same time, a handful of cases signal that there are limits to the deference that agencies enjoy post-Seven County. Agencies continue to face litigation risk as a court may find that they failed to satisfy specific regulatory requirements or reasonably explain their approach in the administrative record. 

Background 

As discussed in our prior client alert, Seven County reoriented NEPA review by both narrowing the scope of analysis required under NEPA and requiring greater judicial deference to agency determinations in implementing NEPA. Specifically, the Supreme Court held that courts must afford “substantial deference” to agency judgments in NEPA analysis and decline to “micromanage” fact-dependent decisions so long as they fall within a “broad zone of reasonableness.”³  The Court emphasized that NEPA is “a procedural cross-check, not a substantive roadblock,” and that the ultimate question is whether the agency’s decision was “reasonable and reasonably explained,” not whether the analysis was perfect.⁴ 

Further, the Court clarified the scope of NEPA analysis in two ways. First, NEPA requires agencies to focus on the effects of the “proposed action” (i.e., the “project at hand”), not separate projects that are geographically or temporally distinct, even if those projects are foreseeable.⁵ Seven County makes clear that agencies must have broad latitude to draw a “manageable line” between such projects.⁶ Second, agencies are not required to analyze the environmental impacts of projects over which they have no authority.⁷ The decision did not specifically address how agencies should treat cumulative effects of a proposed action and acknowledged that agencies will need to make judgments in close cases where it is not clear whether one project is separate from another, leaving agencies and lower courts to confront these issues case by case in the highly deferential landscape.⁸

One Year Later: How Lower Courts Are Applying Seven County

Trends

1. Deference permeates all aspects of NEPA review. Courts repeatedly cite Seven County’s admonition that deference is the “bedrock” of judicial review of NEPA claims, and they consistently broadly defer to agencies on methodological choices,¹⁰  range-of-alternatives determinations,¹¹ sufficiency of detail¹² and scope-of-analysis determinations.¹³ Taken together, these decisions confirm that Seven County operates as a cross-cutting constraint on judicial second-guessing of agency determinations regarding the scope of reviews under NEPA. Agencies prevailed in over 80% of the cases we examined, with losses largely confined to narrow, case-specific issues. Generally, if an agency’s analytical choices fall within a “broad zone of reasonableness,” the agency’s review will be found to have satisfied NEPA. For agencies and project proponents, these cases suggest a favorable environment for defending NEPA documents.
2. Agencies have wide latitude to draw a “manageable line” when defining the scope of NEPA analysis. Prior to Seven County, a limited set of cases used the “manageable line” concept to exclude from NEPA review only those activities outside an agency’s jurisdiction.¹⁴ Under Seven County, courts are now especially deferential to agency decisions to exclude impacts from actions that fall outside the reviewing agency’s jurisdiction.¹⁵ Moreover, post-Seven County cases extend the “manageable line” concept to other NEPA scope determinations¹⁶ and consistently uphold agency decisions to exclude geographically or temporally distinct projects and future, contingent actions from the scope of analysis, even if their effects are foreseeable.¹⁷ Courts have not necessarily required agencies to explain the lines drawn on what to exclude—in some cases, courts have simply inferred the lines and then deferred to agencies’ apparent choices.¹⁸  Nonetheless, despite agencies’ broad discretion, project sponsors should work with agencies early to define the proposed action description and scope of analysis, and ensure that the written record reflects a clear rationale for excluding activities as separate in time, place or regulatory authority. 
3. Cumulative impacts remain a potential vulnerability (for now). Courts generally defer to agency assessments of cumulative impacts.¹⁹ Nevertheless, agencies may fall short if they exclude obviously adjacent projects or skip the analysis altogether.²⁰ That said, as discussed in our prior client alert, new NEPA procedures have omitted express requirements to conduct cumulative impact analysis. As time passes, therefore, courts will apply those new procedures, and litigation risk related to cumulative impact analysis likely will decline. For now, the key takeaway is that cumulative impacts remain a potential vulnerability, especially for decisions made under prior procedures, but future risk will depend on how courts interpret and apply the new, more flexible NEPA procedures.
4. There are bounds on the “broad zone of reasonableness.” Even after Seven County, agencies cannot gloss over regulatory requirements or basic administrative law principles.²¹ For example, the District of Washington vacated a Forest Service NEPA analysis because project maps and a “condition-based management” plan were too vague to comply with NEPA’s requirement to ensure a “hard look” at impacts and enable the public to provide meaningful comment.²²  In another case, the District of Alaska held that the Forest Service violated NEPA by defining the project’s purpose and need so narrowly—by baking in projected growth assumptions—that it effectively predetermined the outcome and foreclosed consideration of reasonable alternatives.²³ These post-Seven County agency losses generally suggest that project proponents and agencies should remain attentive to the fundamental tenets of NEPA review and ensure the analysis is reasonable and explained in the record. 
5. Even when courts find that agencies have fallen short, they have gravitated toward remand without vacatur. Seven County underscored that a NEPA deficiency does not necessarily require vacating an agency decision. The central question is whether the agency had sufficient information to make an informed decision.²⁴  Post-Seven County, courts have elected to remand deficient NEPA analyses without vacating the agency decision in cases where the NEPA error was discrete and not structural and where vacatur would have severe on-the-ground consequences.²⁵ For project sponsors, this trend provides some reassurance that NEPA deficiencies are less likely to unravel approvals of projects, particularly where the administrative record demonstrates a substantively informed decision and the equities weigh against project disruption. That said, advancing projects to key milestones (e.g., receiving a Notice to Proceed and initiating construction) can strengthen arguments against vacatur, and project sponsors should ensure that the underlying substantive approvals are well-supported in the record. In a post-Seven County landscape where plaintiffs may shift focus to non-NEPA claims, as discussed below, a defensible record across all governing statutes is increasingly critical both on the merits and in avoiding remedies that lead to extremely costly and disruptive delays.

Issues to Watch

1. Application of Seven County deference beyond NEPA. Some courts have begun applying Seven County’s principles of agency discretion and deference in regulatory matters across other statutes. For example, the Western District of North Carolina deferred to the definition of the “action area” delineated in a Biological Opinion considering effects to protected wildlife and plant species under Section 7 of the Endangered Species Act (ESA), finding that it fell within the “broad zone of reasonableness.”²⁶ The Ninth Circuit similarly invoked Seven County to grant heightened deference to the National Marine Fisheries Service’s critical habitat designations under the ESA.²⁷ To date, courts have not explicitly applied Seven County principles to reviews of historic properties under Section 106 of the National Historic Preservation Act (NHPA), but the procedural similarities between Section 106 and NEPA suggest that there are arguments supporting increased deference in those areas as well. 
2. Shifting plaintiff focus to other statutes. Given the increased difficulty of prevailing on NEPA claims, plaintiffs will likely shift their focus to other statutes, including the ESA, the NHPA, and substantive authorizing and land management statutes. Ensuring that the record demonstrates compliance with these other statutes and supports a substantive decision will be critical for the long-term durability of federal approvals. 
3. Interpretation of new NEPA procedures. The court decisions since Seven County generally relate to agency actions developed under prior NEPA frameworks, including the now-removed Council on Environmental Quality regulations.²⁸  As courts begin reviewing agency actions under the current frameworks—which generally afford agencies greater discretion and impose fewer prescriptive analytical requirements (including, in many cases, eliminating a stand-alone cumulative effects analysis)—we expect the basis for further judicial deference on outstanding issues such as cumulative effects to be stronger, a point on which agencies have lost even post-Seven County.²⁹

Conclusion

One year after Seven County, the emerging case law confirms that the decision has meaningfully reshaped the NEPA landscape in ways that favor agencies and project proponents. Courts are consistently applying a highly deferential standard of review, giving agencies broad latitude to define the scope of analysis and to make methodological judgments, while limiting successful challenges to narrow, record-specific deficiencies. At the same time, Seven County has not eliminated litigation risk: Agencies—and applicants working with them—must continue to ensure that NEPA analyses and the agencies’ subsequent substantive decisions are grounded in the governing regulations and procedures, clearly explained in the administrative record and coordinated with compliance under all applicable environmental statutes. While project proponents will likely experience greater certainty afforded by Seven County, continued evolution in the case law is anticipated in the coming months.

WilmerHale advises clients across industries on issues relating to project design and siting, federal and state permitting, environmental review under NEPA and analogous statutes, stakeholder engagement and agency negotiations, and related enforcement and litigation. Drawing on experience before key federal and state agencies and deep cross‑disciplinary capabilities, we help clients navigate complex and evolving regulatory frameworks, develop and permit large-scale projects, and manage associated litigation and compliance risks.