Mark W. Mattioli, Fox’s chief deputy attorney general, and Jon Bennion, his deputy attorney general, wrote the state’s answer to the lawsuit.

They said a number of the claims made by the same-sex couples in their lawsuit consisted of arguments, legal claims or conclusions of law that don’t require a response and therefore are denied.

At one point, the state said the U.S. Supreme Court, in its 2013 ruling in United States v. Windsor, reaffirmed that “definition and regulation of marriage” is “within the authority and realm of the separate states.”

In another section, the state attorneys wrote: “Defendants (the state and local officials), however, affirmatively allege that plaintiffs cannot state a claim based upon sex discrimination because men and women, regardless of sexual orientation or preference, are treated the same. Neither men nor women can marry persons of the same gender.”

In another, the state attorneys wrote that “Montana’s recognition of marriage as between one man and one woman does not constitute or impose an unconstitutional stigma or second-class citizenship on persons in same-sex relationship.”

Same-sex marriage is now legal in 19 states and the District of Columbia. Bans have been overturned in 12 states, where appeals are in progress.