## Facts

- Glacier Bay National Park in Alaska contains ecologically sensitive wildlife and is protected as a national park and preserve.
- Increased marine tourism, including large cruise ships, led the National Park Service (NPS) to revise its vessel management plan to allow substantially more vessel entries during the peak season (approximately a 32% increase).
- NPS prepared an environmental assessment (EA) under NEPA and issued a Finding of No Significant Impact (FONSI), concluding an environmental impact statement (EIS) was unnecessary.
- The EA and FONSI acknowledged that increased vessel traffic would have definite effects on wildlife (including humpback whales), but repeatedly stated the magnitude of those effects was unknown due to gaps in scientific information.
- NPS relied in part on mitigation measures (including operational restrictions) while acknowledging that the effectiveness of mitigation had not been empirically studied and remained uncertain.
- National Parks and Conservation Association (NPCA) sued, arguing the FONSI was arbitrary and capricious given uncertainty and potential harm to park resources; the district court granted summary judgment to NPS.

## Issues

1. Whether NPS acted arbitrarily and capriciously under NEPA by issuing a FONSI and declining to prepare an EIS for the increased vessel traffic in Glacier Bay despite acknowledged uncertainty and potential significant impacts.
2. Whether the expansion decision adequately accounted for ANILCA’s protective purposes for Alaska park resources when proceeding without a full EIS.

## Decision

- The Ninth Circuit reversed the district court’s summary judgment for NPS.
- The court held NEPA required preparation of an EIS because the project involved potential significant impacts in a uniquely sensitive area and the record showed substantial scientific uncertainty and unknown mitigation effectiveness.
- The court ordered vacatur of the FONSI and the authorization for increased vessel entries and remanded for preparation of an EIS.
- A dissent argued the majority gave insufficient deference to agency expertise and that uncertainty alone does not mandate an EIS.

## Legal Principles

- An agency may not rely on a FONSI where the record shows effects that are highly uncertain or involve unique or unknown risks, particularly in an ecologically exceptional setting.
- A FONSI must be supported by a convincing explanation that anticipated impacts are not significant; acknowledged knowledge gaps and speculative assumptions about mitigation are insufficient.
- Mitigation can support a FONSI only when the agency demonstrates, with record support, that mitigation will reduce impacts to a non-significant level.
- NEPA requires a “hard look” before committing to action; deferring key questions to future monitoring does not substitute for an EIS when significant effects are reasonably possible.

## Conclusion

The Ninth Circuit required an EIS for NPS’s increased Glacier Bay vessel-entry plan because the agency’s own analysis acknowledged definite impacts, uncertain magnitude, and unproven mitigation, making the FONSI arbitrary and capricious under NEPA.


Nat'l Parks & Conservation Ass'n v. Babbitt, 241 F.3d 722 (9th Cir. 2001)