The Denver-based 10th U.S. Circuit Court of Appeals ruled in a split 2-1 decision against the U.S. Environmental Protection Agency when it declared in 2013 that more than three million acres around Riverton remained legally in Indian Country.

The EPA responded to a request 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, which mean using boundaries of the reservation set in 1868 before a pivotal 1905 Congressional Act.

Wyoming Gov. Matt Mead said in 2013 the EPA erred in its analysis of area history, with potential effects on criminal jurisdiction, taxation and administration.

Wednesday, Mead praised the Circuit Court's decision in a press release, saying the EPA overstepped its authority.

He also vowed to work with the Tribes to improve life on the Reservation, he said. "This case was never about the Tribes’ ability to manage air quality on the Reservation – they should be applauded for their work. Now that both federal and state courts recognize the correct boundary of the Reservation, we look forward to working with the Tribes in their efforts to develop environmental programs."

Wednesday's decision centered on "whether Congress diminished the boundaries of the Wind River Reservation in Wyoming in 1905," 10th Circuit Court Chief Judge Timothy Tymkovich wrote. "We find that it did."

They reviewed the history of the Native Americans the settlers, and the creation of reservations in the 19th century.

"Recognizing the potential for conflicts, particularly over land, the United States negotiated a series of treaties and agreements with dozens of tribes, include the Eastern Shoshone," the judges wrote. The Northern Arapaho Tribe, a traditional enemy of the Eastern Shoshone, was eventually located on the Wind River Reservation.

The first treaty in 1863 established a 44-million acre "Shoshonee County," but that was substantially reduced after settlers came west after the Civil War. Chief Washakie successfully negotiated the Second Treaty of Fort Bridger in 1868 with the Shoshone Tribe and the federal government to preserve three million acres in the Wind River Valley.

But land issues persisted because settlers wanted Indian lands. Over the next several decades, the tribes sold off more of their lands, but sometimes they resisted the government's offers of money.

In 1904, the U.S. Supreme Court declared Congress had unconditional authority over relations with Native Americans, "so Congress no longer needed tribal approval to change reservation boundaries," the circuit court judges wrote.

That year, Wyoming Rep. Frank Mondell introduced a bill initiating the cession of the land north of the Big Wind River. The bill passed in 1905 said in part the Indians, "do hereby cede, grant and relinquish to the United States, all right, title, and interest which they may have to all the lands embraced within said reservation, except the lands within and bounded by the following lines...."

Meanwhile, Indian Inspector James McLaughlin advised the tribes, "'It is believed that it will be to the best interests of your two tribes to cede to the United States the portions referred to.'"

Subsequent legal actions arose about land use, the meaning of public lands, legal jurisdictions, water rights and other issues, but the 1905 Act -- with the word "cede" meaning diminishment -- stands firm, two judges wrote.

The issues may not be settled, however, because the 10th Circuit decision runs counter to another circuit court decision over a similar issue.

In a 14-page dissent, Circuit Court Judge Carlos Lucero wrote the two-judge majority wrongly understood how the federal government's actions as a trustee to sell tribal lands for a conditional promise of payment meant Congress intended to diminish the Reservation.

The 1905 Act, Lucero wrote, did not restore the lands at issue to the public domain. The Act held them in trust and, until they were sold, remained Indian lands. Land sales in the opened area were largely a failure, with less than 10 percent of the land being sold to non-Indians, Lucero wrote. "Today, approximately 75 % of the lands opened for settlement by the 1905 Act is held in trust by the United States for the benefit of the Tribes and their members."

Lucero cited a 1992 U.S. Supreme Court decision that referred to disputes between governments and Indians. "Statutes are to be construed liberally in favor of the Indians, with ambiguous provisions interpreted to their benefit."

More From 101.9 KING-FM