CHEYENNE, Wyo. (AP) — Gov. Matt Mead has written to Environmental Protection Agency Administrator Gina McCarthy saying Wyoming won't honor her agency's determination that over 1 million acres around Riverton is legally Indian Country.

Mead says Wyoming will go to court to contest the decision the EPA announced earlier this month that a 1905 federal law that opened part of the Wind River Indian Reservation to settlement by non-Indians didn't extinguish the land's reservation status.

The EPA decision came in response to an application from the Eastern Shoshone and Northern Arapaho tribes to treat the reservation as a separate state for purposes of implementing the federal Clean Air Act.

Mead says the ruling raises issues of criminal jurisdiction, taxation and administration. He says Wyoming will ignore the EPA ruling until the courts decide.