The U.S. Court of Appeals for the 1st Circuit this week delivered a sharp, clear message to the Wampanoag Tribe of Gay Head (Aquinnah) — it has the right to operate an electronic bingo parlor on its protected tribal lands.

In a stunning reversal, a three-judge panel on Monday unanimously rejected arguments by the town of Aquinnah, the state and a community group, and sided with the tribe on critical points.

The pivotal issues were whether the tribe qualified for gaming under the federal Indian Gaming Regulatory Act (IGRA) and, if so, whether IGRA trumped an earlier settlement act for the Aquinnah tribe that was endorsed by Congress.

U.S. District Judge F. Dennis Saylor 4th had ruled for the town, state and Aquinnah/Gay Head Community Association in late 2015, finding that the tribe does not have the right to conduct Class II gambling (electronic bingo). The decision issued Monday by the appeals court panel reversed Judge Saylor and remanded the case back to the district court for entry of judgment in favor of the tribe.

“Because we find that the tribe has exercised more than sufficient governmental power to satisfy the requirements of IGRA, and the federal [settlement] Act has been impliedly repealed by IGRA in relevant part, we reverse,” wrote Judge Juan R. Torruella for the court.

The decision was released on the same day that members were celebrating the tribe’s 30th anniversary of receiving federal recognition. In a statement, tribal chairman Cheryl Andrews-Maltais hailed the ruling. “This decision affirms our sovereign rights and jurisdiction over the land that has always been ours and solidifies our place in the gaming market,” she said.

Attorney General Maura Healey’s office said it was reviewing the decision and had no immediate comment.

At a special meeting early Thursday afternoon, Aquinnah selectmen met in executive session to discuss strategy. Following the meeting town administrator Adam Wilson said the selectmen agreed “to pursue and research every aspect of an appeal,” consult lawyers for the state and community association and meet again April 20. Selectman Jim Newman is away and did not attend the meeting.

“The bottom line is the board wants to move forward,” said town counsel Ronald H. Rappaport, after the session. “They’re just trying to find out who else is moving forward and what the other cost implications, etc., might be.” He declined to outline all the options, but said asking the full circuit court to consider the case and asking for Supreme Court review are examples.

Speaking to the Gazette earlier in the week, selectman Juli Vanderhoop, who is also a member of the tribe, reiterated her opposition to a casino in town. “We do not have the infrastructure on the Island to carry something like this,” she said by phone, noting ongoing efforts to manage the town budget in Aquinnah.

Larry Hohlt, president of the community association, said his organization would meet within the next few weeks to decide a way forward.“We were disappointed in this opinion and are assessing what is the appropriate for us and all parties to proceed,” he said. “We haven’t really decided at this point.”

The ruling is the latest dramatic turn in a legal battle over the tribe’s attempts to build a gaming operation in a 6,500-square foot community center at the western tip of the Island. Tribal leaders have insisted they have the right to decide whether or not to conduct class II gaming on its lands, and point to a gaming facility’s potential for economic development.

The latest ruling substantially narrows the town’s options to block any such facility. While no one expects a gambling hall to open overnight, the town, state and community group face a steep climb either to get the full circuit court to reconsider the decision or to prevail before the U.S. Supreme Court.

After Judge Saylor’s decision in November 2015, tribal leaders announced that the vacant, unfinished building targeted for the casino would instead be completed for its original purpose — as a community center. The ruling from the appeals court this week could portend an about face for that plan, although in her statement, Ms. Andrews-Maltais said the tribe is still reviewing the ruling and did not address the immediate future of the community center. She did say she hoped the legal opposition to the facility would now end and lead to greater cooperation between tribe and town.

“All tribal economic development is for the express purpose of providing the necessary governmental programs and services for tribal members, but those benefits expand to the community as a whole,” the statement said. “This decision benefits us all.”

The town has consistently argued that the tribe forfeited its right to operate a gambling facility in Aquinnah when it signed a land claims settlement agreement in 1983 that four years later was codified by Congress. Coming soon after the Gay Head Wampanoags had won federal recognition, the 1987 compact gave the tribe 485 acres of land and expressly required compliance with state and local laws, including prohibitions on gaming. IGRA was passed the next year by the same Congress, setting up a national regulatory system for tribes to conduct gaming, but it did not invalidate the prohibitions in the earlier settlement act, according to Judge Saylor’s decision.

The appellate court disagreed, ruling that the tribe exerted sufficient governmental authority to trigger IGRA, and that IGRA trumps the settlement act. Judge Torruella found that the appellants’ legal arguments framing the standard for sufficient governmental authority missed the mark.

“The town gets it backward,” he wrote in part, quoting IGRA as intending gaming to promote economic development, self-sufficiency and strong tribal government. “The town now seeks to put this logic on its head by requiring the tribe’s government to be fully developed before it can have the benefit of gaming revenues. This is not what IGRA requires, nor is it our case law.”

The appellate panel contrasted the Aquinnah case with the court’s past ruling over the Passamaquoddy tribe of Maine, and the reasons IGRA did not trump that tribe’s settlement act.

The Passamaquoddy tribe’s prohibition survived because its settlement act had specific language warning Congress that subsequent laws like IGRA would not apply “unless specifically made applicable within the state of Maine.” IGRA did not contain such specific language.

The gambling prohibition in the settlement acts of the Aquinnah and also the Narragansett tribe of Rhode Island say “nothing about the effect of future federal laws …” the appeals court said. Therefore, IGRA and their settlement acts were in conflict and IGRA, as the more recent federal legislation, must prevail, the appellate court found.

Experts who follow the industry in New England were not surprised by the decision, but pointed to a gaming market that has grown increasingly competitive and could be showing signs of saturation.

Richard A. McGowan, a professor of economics and management at Boston College, said a tribal gaming facility in Aquinnah would face a host of challenges, including competition from the bigger, well-heeled projects. And the remote location at the western end of the Vineyard would discourage repeat patrons who are the lifeblood of casinos, he said.

“The market is really getting saturated,” said Mr. McGowan. “They [the Aquinnah] won all right, but they won way too late.”

The state law that allows casino gambling provides for one license to be issued to a native American tribe, but that license has already been awarded to the Mashpee Wampanoags, whose plans to open a casino are currently tied up in federal court.

Tribal leaders have viewed a gambling operation as the best available opportunity to create revenue for its programs and services — as much as $5 million annually, according to a tribe-commissioned study — while gaining some self-sufficiency.

The town of Aquinnah, one of the poorest in the state, has warned about the impact of a gambling facility on fire, police and other services.

More abstractly, the culture clash of a gambling culture and the Island ethic of natural beauty and pristine environment has worried many Vineyard residents, both inside and outside the tribe.

Ms. Vanderhoop, the selectman and tribal member, concluded : “It doesn’t matter whether it’s big or small, I know only the ill that gaming would bring to any community, never mind a small community like this. Speaking from a tribal point of view, this land is our homeland . . . . I think it might be great for saying that the tribe is sovereign by itself, but what it says for the community is unfortunate.”