## Facts

- The Bureau of Land Management (BLM) manages the Twin Peaks Herd Management Area (HMA), a large area on the California–Nevada border designated for long-term maintenance of wild horses and burros.
- Under the Wild Free–Roaming Horses and Burros Act, BLM must manage the HMA to maintain a “thriving natural ecological balance,” including by setting Appropriate Management Levels (AMLs) and addressing populations above AML as “excess.”
- In 2010, BLM determined the wild horse and burro population at Twin Peaks exceeded AML and was degrading forage and habitat.
- BLM planned and executed an August–September 2010 gather to capture animals using helicopters and horseback ropers, transport them to holding facilities, and then sort animals for release, adoption/long-term holding, or humane destruction in limited circumstances.
- The plan included administering a porcine zona pellucida (PZP) contraceptive vaccine to certain released mares to reduce fertility.
- BLM prepared an Environmental Assessment (EA) and issued a Finding of No Significant Impact (FONSI), declining to prepare an Environmental Impact Statement (EIS).
- Animal-protection organizations and individuals sued, alleging the gather violated the Wild Horses Act and NEPA; the district court granted summary judgment for the government, and plaintiffs appealed.

## Issues

1. Whether BLM violated 16 U.S.C. § 1333(b)(2) by conducting a large gather without following the statute’s specified order and priority for destroying and removing excess animals.
2. Whether the Wild Horses Act required Twin Peaks to be treated as a statutorily designated “range,” limiting BLM’s management discretion as plaintiffs argued.
3. Whether BLM lacked authority to gather and temporarily relocate non-excess animals as part of the operation.
4. Whether BLM violated NEPA by failing to take a sufficient “hard look,” particularly regarding PZP and long-term effects, and by issuing an EA/FONSI rather than preparing an EIS.

## Decision

- The Ninth Circuit affirmed summary judgment for the federal defendants and intervenors.
- The court held the Wild Horses Act did not bar the gather and did not require BLM to destroy animals on-range before conducting a roundup.
- The court rejected the claim that Twin Peaks had to be designated or managed as a statutory “range” in the manner plaintiffs asserted.
- The court held BLM could temporarily gather, hold, treat, and return some animals as part of its statutory management authority.
- The court upheld the EA and FONSI, concluding BLM reasonably found no significant environmental impact and was not required to prepare an EIS.

## Legal Principles

- Under the Wild Horses Act, BLM has broad discretion to manage wild horses and burros to maintain a thriving natural ecological balance, including implementing gathers and population-management measures.
- The statutory “order and priority” in 16 U.S.C. § 1333(b)(2) governs the disposition of excess animals once removal decisions are made; a gather is a preliminary management step and is not itself the statutory “removal” addressed by the priority provision.
- The Act does not compel formal “range” designation for every area meeting a definitional description and does not invalidate management of an HMA absent such designation.
- BLM’s general management authority permits temporary off-range holding, sorting, and treatment (including fertility control) when reasonably related to achieving ecological balance and consistent with the agency’s population-management determinations.
- Under NEPA, an EA and FONSI suffice if the agency takes a hard look at environmental consequences and reasonably determines the action will not significantly affect the environment; scientific uncertainty does not automatically require an EIS when the agency addresses the issue and explains its conclusion.

## Conclusion

The Ninth Circuit upheld BLM’s Twin Peaks gather, construing the Wild Horses Act to allow large-scale gathers and temporary handling of animals as management tools, and holding that BLM’s EA/FONSI satisfied NEPA because the agency reasonably evaluated impacts, including the use of PZP, and found no significant environmental effect.


In Defense of Animals v. U.S. Dep’t of the Interior, 751 F.3d 1054 (9th Cir. 2014)