In this Oct. 4, 2021, photo, the Supreme Court is seen on the first day of the new term, in Washington. Credit: J. Scott Applewhite / AP

PORTLAND, Maine — The U.S. Supreme Court on Monday declined an appeal by the Penobscot Indian Nation in its fight with Maine over ownership and regulation of the tribe’s namesake river.

It was a bitter defeat for the tribe that sued a decade ago, claiming the Penobscot River is part of its reservation.

A federal judge previously ruled that the reservation includes islands of the river’s main stem, but not the waters. There were appeals to a panel of the 1st U.S. Circuit Court of appeals and then to the full appeals court.

On Monday, the U.S. Supreme court, without comment, declined to hear the tribe’s appeals over river regulation.

The Penobscots sued in 2012 after then-Attorney General William Schneider issued an opinion that the tribe’s territory was limited to islands.

The tribe said the lawsuit was necessary to protect tribal authority over its ancestral river. But state regulators argued that a win by the tribe would create “a two-tiered system” on the Penobscot that would be a detriment to the general public.

The ruling came as the Maine Legislature was considering several measures that relate to tribal sovereignty.