BANGOR, Maine — The Penobscot Indian Nation has sued the Maine attorney general and the heads of the Maine Department of Inland Fisheries and Wildlife and the Maine Warden Service over who has authority over the waters of the Penobscot River surrounding the reservation.

The complaint, with a letter written earlier this month by Attorney General William Schneider and another written in 1988 by then Attorney General James Tierney attached, was filed Monday in U.S. District Court in Bangor.

Representatives for the attorney general’s office and DIF&W declined to comment on the case. Efforts to the tribe’s attorney were unsuccessful Wednesday.

The tribe is seeking an injunction to keep Maine game wardens from policing the river and preventing tribal members from engaging in sustenance fishing.

“The [Penobscot] nation has exercised exclusive jurisdiction over sustenance fishing by its members in the waters of the Penobscot River surrounding Indian Island and other islands in the river northward thereof from time immemorial and currently does so pursuant to law duly promulgated and enacted by the nation,” the lawsuit filed by Kaighn Smith of Portland, the tribe’s attorney, said.

“The nation’s jurisdiction over sustenance fishing by its members in the Penobscot River is an exercise of its inherent sovereign authority, as a matter of federal law, and it remained intact; it has never been surrendered by treaty or by an act of Congress,” the lawsuit claimed.

The lawsuit was filed after the tribe received a copy of a letter dated Aug. 8 and signed by Schneider. The letter, which was addressed to Chandler Woodcock, commissioner of DIF&W, and Col. Joel Wilkinson of the warden service, said the tribe has the authority to regulate hunting, trapping and the taking of other wildlife on Indian Island and the islands that the tribe owns north to Medway but not on the Penobscot River.

Wilkinson said Thursday in an email that he asked Woodcock to seek the attorney general’s opinion on who has jurisdiction on the river.

“In recent months, the Penobscot Tribe has disagreed with the State of Maine’s long standing interpretation regarding the jurisdiction of a portion of the Penobscot River that stretches approximately 55 miles,” the head of the warden service said. “This circumstance has caused confusion among user groups that enjoy the many recreational opportunities that the river provides to both Penobscot tribal members and citizens and visitors to the state of Maine. The Maine Warden Service requested, for enforcement purposes, clarification and guidance through the Maine attorney general’s office.”

“Like private landowners, the Penobscot Nation may also restrict access to their lands, here islands, as it sees fit,” Schneider wrote in response to Wilkinson’s request. “However, the river itself is not part of the Penobscot Nation’s reservations, and therefore is not subject to its regulatory authority or proprietary control.

“The Penobscot River is held in trust by the state for all Maine citizens, and state law, including statutes and regulations governing hunting, are fully applicable there,” he continued. “Accordingly, members of the public engaged in hunting, fishing or other recreational activities on the water of the Penobscot River are subject to Maine law as they would be elsewhere in the state, and are not subject to any additional restrictions from the Penobscot Nation.”

That is in direct conflict with Tierney’s letter dated Feb. 16, 1988. Tierney’s letter, which was addressed to William Vail, chairman of the Atlantic Sea Run Salmon Commission, said that the Penobscot and Passamaquoddy tribes are authorized to take fish within the boundaries of their respective Indian reservations so long as the fish are used for their individual sustenance.

Both men based their opinions on the Maine Indian Claims Settlement Act, according to the letters.

The lawsuit claims the 1980 law passed by Congress “expressly confirmed that the Penobscot Nation and its members retain a sovereign right to take fish from the Penobscot River by ratifying [a law] entitled ‘Sustenance Fishing within the Indian Reservations’ which provide, in pertinent part, that notwithstanding any law of the state, members of the Penobscot Nation ‘may take fish, within the boundaries of their … Indian reservation, for their individual sustenance.’”

State officials, who had not yet been served with the complaint, have 21 days to file an answer to it after the complaint is received.