Minn. Stat. § 602.02: FACT OF MARRIAGE, HOW PROVED.

When the fact of marriage is required or offered to be proved before any court, evidence of the admission of such fact by the party against whom the proceeding is instituted, or of general repute, or of cohabitation as married persons, or any other circumstantial or presumptive evidence from which the fact may be inferred, shall be competent.