The legal group representing the Tulsa County clerk defending Oklahoma's gay marriage ban announced Friday it would appeal its appeals court loss to the U.S. Supreme Court.

The Tenth Circuit Court of Appeals in Denver struck down the ban as invalid on July 18, roughly two weeks after it upheld a lower court's ruling striking down Utah's ban.

Unlike the majority of the dozens of cases challenging bans across 31 states, Oklahoma's challenge was filed before the Supreme Court's landmark 2013 ruling striking down a key provision of the Defense of Marriage Act (DOMA), which led to the federal government's recognition of the legal marriages of gay couples.

Plaintiffs Mary Bishop and Sharon Baldwin filed their lawsuit shortly after Oklahoma voters in 2004 overwhelmingly (76%) approved Question 711, which defines marriage as a heterosexual union and prohibits the state from recognizing gay couples with civil unions.

“Although we aren't surprised by the Alliance Defending Freedom's decision to appeal our victory from the 10th US Circuit Court of Appeals, neither are we disappointed,” the couple said.

“We are ready to see the highest court in the land affirm that marriage equality is the law of the land. We have confidence in our case and our lawyers, and should the Supreme Court agree to hear our case, we anticipate a victory there, as well,” they added.

Federal appeals courts have also invalidated state marriage bans in Utah and Virginia. Defendants in those challenges also said they would appeal to the Supreme Court and skip review by a full appeals court.