In 2004, Oklahoma voted to amend the state constitution to define marriage as "the union between one man and one woman," in an explicit sign of its objection to same-sex marriages becoming legal in the state.

Ryan Kiesel, executive director of the Oklahoma affiliate of the American Civil Liberties Union (ACLU), told Al Jazeera that Pickel's marriage will likely not be recognized by the state.

"I think this marriage under tribal law will likely not be recognized," he said. "But I think the federal government will recognize this marriage, and fully anticipate that they will."

The attorney general's office of Oklahoma told Al Jazeera in an email it "does not have any comment" on the legality of the marriage.

The ACLU's Kiesel said he believes the marriage will help raise awareness about the issue in a state that he said is perceived as one of the last ones that would allow same-sex marriage.

"The more concrete examples that people have of same-sex marriages in practice, the harder it will be to enforce discriminatory policies," he said. It's happening within our borders," he added. "And the sky is not falling."

Pickel said he was overwhelmed by the level of support he has received. A friend told him Tuesday he needed to add gifts to his wedding registry at stores such as Target and Walmart, because people had already bought everything the couple had listed.

"About six years ago we were denied entrance to a hotel because we were gay," Pickel said. His marriage, he added "makes it a lot better."

With wire services