Mont. Code Ann. § 39-2-305
39-2-305 Employment of aliens not lawfully authorized to accept employment prohibited
39-2-305 . Employment of aliens not lawfully authorized to accept employment prohibited. (1) No employer may knowingly employ an alien who is not lawfully authorized to accept employment.
(2) A person convicted of violating this section shall be fined no more than $300.
(3) The department of labor and industry or a person harmed by a violation of this section may sue to enjoin an employer from violating this section and to gain other appropriate relief.