Advocates of same-sex marriage predict gay marriage soon will be a reality in Montana.

Four gay couples filed suit in May seeking the right to marry in Montana. U.S. District Judge Brian Morris is scheduled to hear arguments in that case in Great Falls on Nov. 20.

Liz Welch with the Montana ACLU says she's not 100 percent sure Morris will rule in the couples' favor, but she's encouraged by recent rulings allowing gay marriage in other states.

The Bozeman Chronicle reports three of the four couples suing have been married in other states but their marriages aren't recognized in Montana.

They've asked Morris to strike down Montana's constitutional ban on gay marriage.