U.S. District Judge Karen E. Schreier ruled Monday against South Dakota’s constitutional amendment banning marriage equality.

South Dakota is the latest state to see such a ban struck down in court since the U.S. Supreme Court handed down its historic marriage rulings in June 2013.

In Rosenbrahn v. Daugaard, private attorneys and the National Center for Lesbian Rights sued the state on behalf of six same-sex couples that argue that South Dakota’s ban on marriage equality violates the U.S. Constitution.

“According to Judge Schreyer’s ruling and two dozen others over the last year, there is no justifiable reason to keep these discriminatory marriage bans on the books, said Human Rights Campaign legal director Sarah Warbelow. “The truth is, laws prohibiting same-sex couples from marrying serve no purpose other than to harm Americans who simply want to protect and provide for themselves and their families.”

The state now has the option to appeal today’s order to the Eighth Circuit Court of Appeals. Presently two other states – Arkansas and Missouri – have appealed similar U.S. District Court rulings to the Eighth Circuit.