Mont. Code Ann. § 13-2-112

Each election administrator shall keep an official register of electors in the statewide voter registration system. The original signed registration form for each elector must be scanned, and the scanned copy must be retained in the statewide voter registration system. The original paper copy must be kept according to the state records retention schedule for such records. The information recorded in the official register of electors and the design of the registration forms must be prescribed by the secretary of state in the statewide voter registration system.