The Osage Nation has voted to change the definition of marriage in an election that drew an overwhelming number of absentee ballots.
The tribe will now define marriage as a union between "two persons" rather than "a man and a woman."
More than 1,100 people sent in absentee ballots but only 347 people showed up for onsite balloting during a two-day early voting period and on Monday, the actual election day.
Election Board member Shannon Lockett told Tulsa television station KTUL that she was surprised by the low in-person turnout given the importance of the initiative.
Osage Nation Congresswoman Alice Buffalohead sponsored the proposal, saying there was enough discrimination in the world and that all Osage should be treated equally.
The proposal passed with 53 percent of the vote.