Four gay and lesbian couples on Wednesday filed a lawsuit in state court in Cheyenne challenging Wyoming's laws prohibiting gay couples from marrying.

The lawsuit challenges Wyoming's statute barring such unions and the state's refusal to recognize the out-of-state legal marriages of gay couples, arguing that Wyoming's marriage laws violate the Wyoming Constitution's guarantee of equal protection and due process.

Plaintiff couples are Cora Courage and Wyoma “Nonie” Proffit of Evanston, Carl Oleson and Rob Johnston of Casper, Anne Guzzo and Bonnie Robinson of Laramie, and Ivan Williams and Chuck Killion of Cheyenne.

Wyoming Equality, the state's largest LGBT rights advocate, filed the lawsuit on behalf of the four couples, who are represented by attorney Tracy Zubrod, the law firm of Arnold & Porter LLP, the law firm of Rathod Mohamedbahi LLC, and the National Center for Lesbian Rights (NCLR).

“The law should support stable families, not make it harder for committed couples to support one another and protect their children,” Shannon Minter, legal director for NCLR, said in a statement announcing the lawsuit. “Barring same-sex couples from marriage causes great harm to these families and their children while helping no one.”