BANGOR, Maine — The Penobscot Indian reservation includes the islands on the main stem of the Penobscot River but not the water itself, a federal judge ruled Wednesday.

U.S. District Court Judge George Singal also ruled that members of the tribe may take fish from the entirety of that section of the river for sustenance.

Singal’s rulings came more than three years after the tribe filed a lawsuit against the state as a result of former Attorney General William Schneider sending a letter dated Aug. 8, 2012, to the tribal warden service saying that the state, not the tribe, has the authority to charge people with violating fishing regulations and water safety rules, according to court documents.

The tribe alleged in the lawsuit that its reservation includes the water in the river because of the tribe’s sustenance fishing rights. A year later, municipalities along the river were granted intervenor status in the case and supported the state’s contention that the reservation included the islands but not the water. The municipalities claimed that a ruling in the tribe’s favor would give it control over water quality on the river and allow the tribe to impose stricter rules than the state does on municipal discharges into the river.

Singal based his decision in part on language in the 1980 Maine Indian Claims Settlement Act, which defined the Penobscot Indian Reservation as the islands “consisting solely of Indian Island, also known as Old Town Island, and all islands in that river northward.”

“There is, in the court’s view, no ambiguity in these definitions,” Singal wrote in his 64-page decision. “MICSA is explicitly silent on the issue of any waters being included within the boundaries of the Penobscot Indian Reservation because [the statute] speaks only of ‘lands.’”

The statutes that cover most other tribes around the nation use the phrase “land and natural resources,” the judge wrote.

“Thus, [MICSA’s] use of the word ‘lands,’ instead of the more broadly defined phrase ‘land and natural resources,’ appears to reflect a congressional focus on defining only what land would make up the ‘Penobscot Indian Nation.’”

As for the issue of sustenance fishing rights, Singal found that the “undisputed record shows a long history of Penobscot Nation members sustenance fishing the entirety of the main stem and an intention on the part of the Maine Legislature, Congress and the Penobscot Nation to maintain this status quo with the passage of the Settlement Acts. In fact, this status quo was maintained in practice, and it was only in the context of this litigation that the state took the position that sustenance fishing rights in the main stem were not guaranteed under [the statute],” the judge said.

Efforts to reach Penobscot Indian Chief Kirk Francis were unsuccessful Wednesday.

The tribe’s attorney, Kaighn Smith Jr. of Portland, said late Wednesday that he was “still digesting the decision” but praised the judge’s ruling on fishing rights.

“We’re delighted the court confirmed the reservation’s sustenance fishing rights bank to bank” he said in a telephone interview. “As for the other rights at issue in the ruling, we need to sort that out.”

Smith declined to speculate on whether the decision would be appealed to the 1st U.S. Circuit Court of Appeals in Boston.

Maine Attorney General Janet Mills said in a statement issued Wednesday afternoon that she was pleased that the judge agreed with the state’s argument that the river is “held in trust for the use and benefit of all people.”

“The state is equally pleased that the court recognized the historical right of individual tribal members to engage in sustenance fishing along the river,” the statement said.

As far as which agency, the Maine Warden Service or the Penobscot Nation Warden Service, enforces regulations on the river, Mills said that her predecessor’s decision that it is the state agency’s responsibility still stands.

“We want to work with the nation in making sure that their rights to sustenance fishing are respected and that water quality standards are imposed and enforced in the tradition of Sens. Edmund Muskie and George Mitchell,” she said.

Attorney Matthew Manahan of Portland, who along with Catherine Connors, represented the municipalities, called the decision a victory.

“This is an important victory in upholding the terms of the Maine Indian Land Claims Settlement Act, and hopefully it will put to rest, once and for all, the efforts to undermine the Settlement [Act] and create the ‘nation within a nation’ construct that the Settlement [Act] was intended to avoid,” he said in an email.

Efforts to reach Assistant Attorney General Steven Miskinis of the Indian Resources Section of the Environmental and Resources Division in the U.S. Department of Justice, who supported the tribe’s position, were unsuccessful Wednesday.

The tribe called the federal government’s involvement in the lawsuit “unprecedented.”

Singal heard oral arguments on cross motions for summary judgement in October in federal court in Portland.