PHOENIX, Ariz. — At least four American Indian tribes have legalized same-sex marriage this year — in some cases creating islands of marriage equality in states that otherwise ban the unions.

As a growing number of states have moved to allow gay couples to wed, with Illinois poised to bring the number to 16 soon, so have tribes, which are sovereign governments not subject to state laws. At least seven perform same-sex marriages, including Oklahoma, Oregon and Michigan, where voters constitutionally banned gay marriage in 2004.

“The federal government recognizes it, but the state I reside in doesn’t,” said Tim LaCroix, 53, a member of the Little Traverse Bay Bands of Odawa Indians in Michigan. LaCroix wed his non-Indian partner of 30 years on tribal land in March. “We should be accepted in the state of Michigan. We pay taxes like everyone else.”

The U.S. Supreme Court’s decision in June striking down a ban on federal benefits for same-sex couples has emboldened marriage rights activists throughout the country, including those on reservations.

The ruling that invalidated the core of the U.S. Defense of Marriage Act didn’t force states to recognize marriages performed elsewhere, including by tribes within their borders, said Ron Whitener, executive director of the Native American Law Center at the University of Washington School of Law. Still, the high court’s action has a direct impact on American Indians who may deal directly with the federal government about reservation land and other issues, he said.

“It’s going to speed up the uptake of same-sex marriage in tribes because it clears up that issue that for Indians is a bigger deal than even for non-Indians,” he said.

There are 566 federally recognized tribes in the U.S. The two largest, the Cherokee Nation and Navajo Nation, banned same- sex marriage in 2004 and 2005, respectively, as similar laws swept through states. Other tribes, like Whitener’s own, the Squaxin Island Tribe in Washington state, don’t have laws governing domestic relations and defer to the state, he said.

Over the past 20 years, there has been a push by tribes to rewrite their laws to better reflect their customs and culture, Whitener said. As that process continues, he said, more tribes will allow same-sex couples to wed. Some tribes traditionally regard homosexuals as highly spiritual people, sometimes referred to as “two-spirited,” he said.

“Gay marriage has a place in the traditional values of many tribes in the United States,” Whitener said.

It’s not known how many tribes explicitly allow gay marriage in their statutes or have been performing ceremonies. Generally, at least one of the spouses would have to be a member of the tribe to qualify for marriage, Whitener said.

The Coquille Indian Tribe in Oregon legalized same-sex marriage in 2008, followed by the Suquamish Tribe of Washington in 2011. The Little Traverse Bay Odawas’ tribal council voted to recognize gay marriage in March — and LaCroix and Gene Barfield, 61, who met in the U.S. Navy, were married immediately after the measure was signed. The Pokagon Band of Potawatomi in Michigan, the Santa Ysabel tribe of California and the Confederated Tribes of the Colville Reservation of Washington state also took legislative action to allow same-sex marriages this year.

“It’s something we have accepted since time immemorial,” said Michael Finley, 35, chairman of the Colville tribes’ council, which voted unanimously to allow gay marriages in September. “If they choose to marry someone of the same sex, they should be allowed to do so, and they shouldn’t be discriminated against.”

The Oklahoma-based Cheyenne and Arapaho Tribes, whose law is silent on gender, performed its first same-sex marriage in December, said Lisa Liebl, a spokeswoman. Its third ceremony Oct. 31 attracted national attention because of the state ban. Darren Black Bear, 45, a member of the tribe who wed his partner, who’s not a member, said he didn’t care if Oklahoma recognized the union or not.

“My tribe recognizes it and what matters is that the federal government recognizes it,” said Black Bear, of Oklahoma City, as he and husband Jason Pickel, 36, drove to Concho to file their marriage license at the tribal court the day after the ceremony.

The couple had planned to wed in Iowa until they learned they could do so on the reservation. Same-sex marriage became legal in Iowa in 2009. In Hawaii, the state Senate passed a bill legalizing gay marriage and it was signed Wednesday by Gov. Neil Abercrombie.

Public attention around the marriage has sparked a backlash and greater scrutiny of tribal code. The tribe’s Supreme Court is reviewing the code, which is vague and refers only to “Indians,” to determine whether one or both spouses need to be Cheyenne or Arapaho or whether non-Indians or members of other tribes may be married, Liebl said.

While some tribal leaders have expressed support for marriage rights, the tribe’s chief of staff has called for a vote of the tribal council or the people on the issue. Ida Hoffman, 60, who described herself as a Baptist, said she thinks media accounts made it seem like all tribal members support same-sex marriage. She wants it banned, she said.

“I’m opposed to same-sex marriage as I’m sure a lot of our tribal members are,” Hoffman said. “I feel like, with an issue like this, it needs to go out to the people.”

The Navajo Nation Council banned same-sex marriages on its 27,000-square-mile reservation that spans Arizona, New Mexico and Utah in 2005 after overriding a veto by the tribal president. But as popular opinion has changed around the country — 55 percent of Americans now support same-sex marriage, according to a Bloomberg National Poll in September — it’s changing on reservations, too, said Alray Nelson, a gay Navajo.

Nelson, 27, helped organize the advocacy group Navajo Equality in the wake of the U.S. Supreme Court’s decision. He and other members are approaching their family, friends and clans to talk about how tribal law discriminates. The group is hoping to challenge the ban in tribal court next year.

“It gave us new energy,” Nelson, a political science student at the University of New Mexico in Albuquerque, said of the Supreme Court decision. “We are sitting down with elders, with parents, in our homes, in our hogans and on front porches. The focus is on family because that is what this law discriminates against; it discriminates against families.”