Even if a U.S. Supreme Court ruling this spring makes same-sex marriage the law, it would leave pockets of the country where it isn’t likely to be recognized any time soon: the reservations of a handful of sovereign Native American tribes, including the nation’s two largest.

Since 2011, as the number of states recognizing such unions spiked to 37, at least six smaller tribes have revisited and let stand laws that define marriage as being between a man and a woman, according to an Associated Press review of tribal records. In all, tribes with a total membership approaching 1 million won’t recognize marriages between two men or two women.

Several explicitly declare that same-sex marriages are prohibited. And some have even toughened their stance.

In December, just weeks after North Carolina began issuing marriage licenses to same-sex couples, the state’s Eastern Band of Cherokee Indians updated its law to add language preventing gay couples from having marriage ceremonies performed on tribal land. The resolution changing the law, which passed 8-1, says court cases around the country prompted the tribe of about 13,000 enrolled members to review its own laws.

The Cherokee Nation in Oklahoma and the Navajo Nation, with about 300,000 members each, maintain decade-old laws that don’t recognize same-sex marriage. Neither tribe has shown much sign of shifting.

Alray Nelson, a gay rights activist who lives with his partner Brennen Yonnie on the Navajo reservation, said the tribe’s law denies same-sex couples the right to be included in decisions on a partner’s health care, or to share in a home site lease. Getting a marriage license would only require a short drive to a courthouse off the reservation, but the couple — both enrolled Navajo members — would rather wait until it’s allowed on the reservation.

“We are both planning to build a life here, and we want to raise a family,” he said. “So it’s not an option for us to remove ourselves from our community.”

As with the states, opposition to gay marriage varies among tribes. At least 10 have recognized same-sex marriage, often well ahead of their surrounding states and without having judges force their hands. Many others are neutral.

The Supreme Court will hear arguments April 28 and could decide by June whether gay couples can marry in the remaining states and U.S. territories where it’s not allowed. But while 27 states that allow gay marriage got dragged over the threshold by judges, the sovereign status of federally recognized tribes means a Supreme Court ruling wouldn’t directly affect their laws.

Cherokee officials in Oklahoma and North Carolina say nothing in their laws prevents members from getting marriage licenses in adjacent counties. The Oklahoma-based Cherokee Nation, which has a separate government and laws from the Eastern Band, passed its marriage law in 2004.

The Navajo Nation Council voted in 2005 to ban same-sex marriages on the 27,000 square-mile reservation that extends into Arizona, New Mexico and Utah — all states where such marriages are legal. Then-President Joe Shirley Jr. vetoed the measure, but lawmakers overturned it.

There’s been no push recently among tribal lawmakers to change that, said council spokesman Jared Touchin.

The Osage Nation, bordering Tulsa, Oklahoma, passed a wide-ranging marriage law in 2012 that doesn’t recognize same-sex unions.

John Hawk Co-Cke’ (co-KAY), an enrolled member of the Osage Nation who’s gay, said that before reservations were created, many tribes had no problem with men who embraced their feminine side and women who lean toward their masculine side, inspiring the term two-spirit people. Two-spirit people were sometimes given special ceremonial roles because of their ability to go into both the masculine and feminine world, he said.

At least 10 tribes — including the Cheyenne and Arapaho Tribes in Oklahoma, the Coquille Indian Tribe in Oregon and the Little Traverse Bay Bands of Odawa Indians in Michigan — have enacted laws since 2009 to recognize gay marriage, according to the New York-based advocacy group Freedom to Marry.

Navajos are set to elect a new president April 21, a week before the Supreme Court hearing. Shirley, the former president who supports same-sex marriage, faces former lawmaker Russell Begaye . But neither man could change the law without lawmakers on board, given the rarity of voter-led ballot initiatives on the reservation where about 185,000 tribe members live.

“It’s a different battle,” said Nelson, the activist. “It’s a different landscape.”