(1) A person commits the offense of marrying a bigamist if the person contracts or purports to contract a marriage with another knowing that the other is committing bigamy. (2) A person convicted of the offense of marrying a bigamist shall be fined not to exceed $500 or be imprisoned in the county jail for any period not to exceed 6 months, or both.
Marrying A Bigamist
Mont. Code Ann. § 45-5-612, under Offenses Against the Family.
Mont. Code Ann. § 45-5-612