CHEYENNE, Wyo. (AP) – The Northern Arapaho Tribe is pushing to join a tribal member’s federal challenge of his state court murder conviction in the 2004 beating death of his daughter.

The tribe late last month asked a federal appeals court in Denver for permission to file a brief supporting Andrew Yellowbear Jr.’s appeal. The Wyoming attorney general’s office opposes the tribe’s request.

Yellowbear, now serving a life sentence in state prison, argues that Wyoming lacked jurisdiction to prosecute him in the death of 22-month-old Marcela Hope Yellowbear. The girl suffered her injuries in Riverton, which he says is “Indian Country.” He maintains that any prosecution of him should occur in tribal or federal court.

Macalia Blackburn, the girl’s mother, pleaded guilty in state court to being an accessory to second-degree murder and was sentenced to 60 years in prison.

In its request to file a friend-of-the-court brief backing Yellowbear, the Northern Arapaho tribe says it wants to support his jurisdictional argument. Yellowbear doesn’t oppose the tribe’s request.

Yellowbear’s attorney, James Drummond of Norman, Okla., didn’t immediately return a telephone message left at his office seeking comment Tuesday.

The tribe says the issues in Yellowbear’s appeal mirror its own appeal pending in the same Denver court in a long-standing boundary dispute.

The tribe has appealed U.S. District Judge Clarence A. Brimmer’s dismissal in October of the tribe’s lawsuit against the state and Fremont County. The tribe says the state and county lack authority to tax tribal members on land around Riverton.

The tribe’s lawsuit focuses on a 1905 act of Congress that opened reservation land around Riverton to settlement by non-tribal members. While the state contends the act removed the land’s legal status as part of the Wind River Indian Reservation, the tribe holds that it did not.

Brimmer, of Cheyenne, dismissed the tribe’s case saying it couldn’t proceed without the participation of the United States and the Eastern Shoshone Tribe. The two tribes share the Wind River Indian Reservation in central Wyoming.

Brimmer also was the judge who denied Yellowbear’s challenge to his state court conviction.

Andrew Baldwin, lawyer for the tribe, argued in his request to the appeals court that it should consider the tribe’s tax case appeal together with Yellowbear’s appeal. Baldwin didn’t immediately respond to telephone messages left at his Lander office Tuesday.

In his brief to the appeals court, Baldwin says the federal courts have already ruled that the disputed area remained reservation land for purposes of a water rights adjudication. He wrote that only Congress can terminate the status of reservation land as Indian Country, and that it never did so in the area around Riverton.

Wyoming Attorney General Bruce Salzburg’s office this week filed a response opposing the tribe’s request to enter Yellowbear’s case, saying the murder case and the tax case raise different issues and should proceed under different standards of review.

“Mr. Yellowbear is adequately represented by his own counsel, and the Northern Arapaho Tribe has nothing to add to the brief presented on Mr. Yellowbear’s behalf,” Senior Assistant Attorney General David Delicath wrote in the response.

Salzburg declined to comment Tuesday.