## Facts

- Asarco LLC operated the Ray Mine Complex in Arizona and sought to expand mining through a land exchange with the Bureau of Land Management (BLM).
- The exchange would transfer 10,976 acres of BLM-managed public land to Asarco in return for roughly 7,300 acres of private land conveyed to the United States.
- Asarco held unpatented mining and millsite claims on some of the federal land; mining beyond casual use on public land would require BLM approval of a Mining Plan of Operations, triggering NEPA and FLPMA review.
- BLM prepared an Environmental Impact Statement (EIS) for the exchange and treated mining as expected to occur under every alternative, including the no-action alternative.
- Based on that assumption, BLM did not analyze whether mining would occur differently (or be subject to different constraints) if the land remained public rather than becoming private.
- BLM issued a Record of Decision approving the exchange and finding it in the public interest.
- Conservation groups sued under the Administrative Procedure Act (APA), alleging NEPA and FLPMA violations; the district court granted summary judgment for BLM and Asarco.

## Issues

1. Whether BLM violated NEPA by assuming mining would occur at the same scale and with the same impacts under both the no-action alternative and the exchange, thereby failing to take a hard look at the exchange’s environmental consequences.
2. Whether the EIS’s alternatives analysis was inadequate because it did not meaningfully evaluate how mining could differ if the land remained public and subject to federal approval conditions.
3. Whether BLM’s FLPMA public-interest determination was arbitrary and capricious because it relied on the same unsupported assumption that mining impacts would not differ between public and private ownership.

## Decision

- The Ninth Circuit reversed the district court’s judgment and remanded.
- The court held BLM violated NEPA because the EIS did not adequately analyze the environmental effects of shifting land from a federal regulatory regime to private ownership, relying on an unsupported baseline assumption that mining would be the same either way.
- The court held BLM’s FLPMA public-interest finding was arbitrary and capricious under the APA because it depended on the same flawed assumption about identical mining impacts.
- A dissent would have affirmed, reasoning BLM’s technical judgments deserved greater deference.

## Legal Principles

- NEPA requires an agency to take a hard look at the environmental consequences of the proposed federal action and to support key predictive assumptions with record-based analysis.
- An EIS may not define the no-action alternative in a manner that assumes away material differences created by the agency’s choice, including differences resulting from changes in land ownership and regulatory control.
- When an agency action may alter the applicable regulatory regime (public land subject to federal approvals versus private land), NEPA requires analysis of how that change may affect the extent, configuration, and impacts of the activity.
- FLPMA land exchanges require a reasoned public-interest determination; a finding premised on unsupported assumptions about unchanged impacts is arbitrary and capricious under the APA.
- Judicial deference to agency technical judgments does not excuse failure to address central analytical gaps required by statute.

## Conclusion

The Ninth Circuit set aside BLM’s approval of the mining-related land exchange because the EIS and FLPMA public-interest finding treated mining impacts as unchanged across alternatives, rather than analyzing how converting public land to private ownership could alter regulatory constraints and environmental outcomes.


Ctr. for Biological Diversity v. U.S. Dep't of the Interior, 623 F.3d 633 (9th Cir. 2010)