CHEYENNE, Wyo. (AP) – The Northern Arapaho Tribe says the U.S. Justice Department has blocked tribal efforts to gain authority to monitor air quality on the Wind River Indian Reservation and the surrounding area.

The Northern Arapaho and Eastern Shoshone tribes nearly five years ago asked the U.S. Environmental Protection Agency to treat their shared central Wyoming reservation as a separate state for purposes of implementing the federal Clean Air Act.

If the EPA approves the application, it would allow the tribes to seek grant money to monitor air quality. Approval also could set the stage for the tribes to seek to impose air quality regulations more stringent than federal standards.

The tribes asked the EPA to accept reservation boundaries that encompass areas around Riverton, Pavillion and Kinnear. Many entities, including the state of Wyoming, have urged the EPA to reject that proposed boundary.

“The tribes’ application, if granted, has implications for criminal law, civil law, water law and taxation,” Gov. Matt Mead wrote the EPA in August. “It also takes away the voices of citizens in Kinnear, Riverton and Pavillion.”

In 2009, then-Wyoming Attorney General Bruce Salzburg commented to the EPA that the tribes’ application covered lands that Congress has removed from the reservation.

Recent court rulings haven’t substantiated Northern Arapaho claims on the area.

The Northern Arapaho Business Council wrote U.S. Attorney General Eric Holder recently, saying the Justice Department blocked the EPA from releasing a decision this summer. Darrell O’Neal, chairman of the business council, signed the letter.

The council’s letter states that officials with the EPA and Interior Department assured the tribes that a decision on the application would come in July. However, the letter says that deadline was hastily dropped after the Justice Department stated it was no longer “on board” with the decision.

O’Neal states that the Justice Department early in the process determined that the Kip Crofts, U.S. Attorney for Wyoming, shouldn’t be involved in the application process. However, it states that, “We are also concerned that recently he has been active, directly or indirectly, despite this exclusion.”

John Powell, spokesman for the U.S. attorney’s office in Cheyenne, said the Justice Department had no comment on the matter.

Mark A. Howell, a lobbyist for the Northern Arapaho Tribe in Washington, D.C., said this week the tribe thinks both the U.S. Department of Interior and the EPA have signed off on the decision.

“Now it is simply the Justice Department that continues to throw up what we believe to be fallacious arguments against it,” Howell said.

“Under the regulations, if the tribes are granted treatment as a state status, any issues that deal within air quality within 50 miles of the exterior boundaries – the tribes would have to be noticed and have the opportunity to comment on those forces,” Howell said.

O’Neal states in his letter to Holder that he’s concerned that large energy companies are also likely to be active to try to influence the decision.

Bruce Hinchey, president of the Petroleum Association of Wyoming, said Thursday he wasn’t familiar with the tribes’ application or any industry attempts to influence its outcome.

Rich Mylott, spokesman for the EPA in Denver, said the agency is reviewing the tribes’ application and is working toward a decision soon. He said it would be inaccurate to say the agency has seen a lobbying effort against the application by the state, the U.S. attorney’s office in Wyoming and industry.

“Our review of the tribes’ application began in 2008 and has included a public process, comments and discussions with several parties, including extensive contact with the tribes and representatives from federal, state and local governments,” Mylott stated.

The “review is focused on a thorough analysis of the tribes’ application, public comments, relevant facts and the specific eligibility requirements under the Clean Air Act,” he said.