## Facts

- The U.S. Fish and Wildlife Service (FWS) listed the Mexican Spotted Owl as a threatened species under the Endangered Species Act (ESA).
- A coalition of Arizona and New Mexico counties sued federal agencies and officials, challenging the listing on procedural grounds and for allegedly insufficient scientific support.
- Dr. Robin Silver, a wildlife photographer and amateur biologist who had studied and photographed the owl, had petitioned for the listing and had engaged in related advocacy and litigation.
- Dr. Silver moved to intervene as of right under Federal Rule of Civil Procedure 24(a)(2) to defend the owl’s listing and related protections.
- The district court denied intervention as of right and permitted only amicus participation.
- Dr. Silver appealed; the denial of intervention was treated as a final, immediately appealable order because it prevented him from becoming a party.

## Issues

1. Whether Dr. Silver satisfied Rule 24(a)(2)’s requirements for intervention as of right, including a significantly protectable interest, practical impairment, and inadequate representation by existing parties.

## Decision

- The Tenth Circuit reversed the order denying intervention and remanded with instructions to allow Dr. Silver to intervene as of right.
- The court found the motion timely.
- The court held Dr. Silver had a direct, substantial, legally protectable interest in the litigation because of his sustained work with the owl and his role in initiating the listing.
- The court concluded the lawsuit threatened, as a practical matter, to impair his interests because invalidation or curtailment of the listing could weaken protections affecting the owl and its habitat.
- The court held the federal defendants might not adequately represent Dr. Silver’s interests because their broader public responsibilities could diverge from his focused interest in a vigorous defense of the listing.

## Legal Principles

- Intervention as of right under Rule 24(a)(2) requires: (1) timely motion; (2) an interest related to the action; (3) potential practical impairment of that interest; and (4) inadequate representation by existing parties.
- The “interest” and “impairment” inquiries are applied pragmatically; the applicant need only show the disposition of the action may impair the ability to protect the interest.
- When the government is an existing party, shared objectives do not automatically establish adequate representation; a proposed intervenor can rebut adequacy by showing possible divergence stemming from the government’s broader mandate.
- The burden to show inadequate representation is minimal.

## Conclusion

The Tenth Circuit held that an individual who initiated and worked to secure ESA protections for a species had a sufficiently protectable interest to intervene as of right in litigation seeking to invalidate those protections, and that federal agencies defending the rule could not be presumed to represent the individual’s narrower conservation interests.


Coal. of Ariz./N.M. Cntys. for Stable Econ. Growth v. Dep’t of the Interior, 100 F.3d 837 (10th Cir. 1996)