Now that the U.S. Supreme Court has confirmed that the Constitution protects the right of same-sex couples to marry under the due process and equal protection clauses of the 14th Amendment, Indian tribes are suddenly the only governmental entities in the United States that have the option not to allow same-sex couples to marry within their jurisdictions. After having been largely left out of conversations about the right to marry, tribes, and particularly those tribes with Defense of Marriage Acts (DOMAs), have overnight become the last frontiers in the fight for marriage equality. And yet, outside of the Indian law bar, little is known about the relationship of federal law to tribal law and about the diverse approaches that tribes take to...