## Facts

- Dwight Dion Sr., a Yankton Sioux tribal member, shot several bald eagles on the Yankton Sioux Reservation and sold at least some carcasses.
- The Yankton Sioux treaty rights at issue were understood to include an exclusive right to hunt and fish on the reservation.
- Dion was charged under federal wildlife-protection statutes, including the Endangered Species Act (for taking bald eagles) and the Bald Eagle Protection Act (for distributing carcasses).
- A district court dismissed a count alleging the shooting of a golden eagle under the Bald Eagle Protection Act.
- A jury convicted Dion of taking bald eagles in violation of the Endangered Species Act and of distributing carcasses in violation of the Bald Eagle Protection Act (and related statutes).

## Issues

1. Whether Congress, through the Bald Eagle Protection Act (as amended) and the Endangered Species Act, clearly and plainly intended to abrogate any treaty right of Yankton Sioux members to hunt bald and golden eagles on the reservation.
2. Whether a treaty-based hunting defense survived for noncommercial eagle taking.
3. Whether, after any abrogation by the Bald Eagle Protection Act, a treaty right could still be asserted as a defense to Endangered Species Act charges for taking bald eagles.

## Decision

- The Supreme Court unanimously reversed the Eighth Circuit in relevant part and remanded.
- The Court held that the Bald Eagle Protection Act, particularly the 1962 amendments extending protection to golden eagles and creating a permit process for “the religious purposes of Indian tribes,” abrogated the treaty right to hunt bald and golden eagles, except as authorized by federal permit.
- Because the treaty right to hunt bald eagles had been abrogated (absent a permit), Dion could not assert a treaty defense to prosecution under the Endangered Species Act for taking bald eagles.
- The Court rejected a noncommercial exception; the statutory prohibitions apply to eagle taking without distinguishing commercial from noncommercial conduct.

## Legal Principles

- Congress may abrogate Indian treaty rights only when its intent is “clear and plain.”
- A comprehensive statutory ban on taking protected wildlife, coupled with a narrowly framed, permit-based accommodation for Indian religious use, can constitute a clear and plain abrogation of treaty hunting rights.
- Courts will not preserve a treaty-based noncommercial hunting right where the statutory text and structure indicate Congress intended to prohibit all unauthorized taking to protect species.
- Once Congress has clearly abrogated a treaty right as to particular wildlife, the treaty right cannot be used as a defense to prosecution under overlapping federal conservation statutes addressing the same conduct.

## Conclusion

The Court held that Congress clearly abrogated the Yankton Sioux treaty right to hunt bald and golden eagles through the Bald Eagle Protection Act’s comprehensive prohibition and limited permit scheme, and that no treaty defense remained to Endangered Species Act charges for taking bald eagles absent federal authorization.


United States v. Dion, 476 U.S. 734 (1986)