State of Wyoming v. Environ. Protect. Ag'y, No. 14-9512 (10th Cir. 2017)Annotate this Case
The Eastern Shoshone and Northern Arapaho Tribes jointly inhabited the Wind River Reservation. The State of Wyoming and the Wyoming Farm Bureau Federation challenged a decision by the Environmental Protection Agency granting the Tribes’ application for joint authority to administer certain non-regulatory programs under the Clean Air Act on the Reservation. As part of their application, the Tribes were required to show they possessed jurisdiction over the relevant land. The Tribes described the boundaries of the Wind River Reservation and asserted that most of the land
within the original 1868 boundaries fell within their jurisdiction. Wyoming and others submitted comments to the EPA arguing the Reservation had been diminished in 1905 by act of Congress, and that some land described in the application was no longer within tribal jurisdiction. After review, the EPA determined the Reservation had not been diminished in 1905 and the Tribes retained jurisdiction over the land at issue. Because the EPA decided the Tribes otherwise satisfied Clean Air Act program requirements, it granted their application. The issue this case presented for the Tenth Circuit's review was whether Congress diminished the boundaries of the Wind River Reservation in Wyoming in 1905. the Court found that it did. The Court therefore granted Wyoming's petition for review, vacated the EPA's order and remanded this case for further proceedings.