Mont. Code Ann. § 19-18-202

The treasurer of an association may not enter upon the duties of office until the treasurer has given the association a sufficient bond of not less than 50% of the amount of the cash funds and securities of the association for the faithful performance of the treasurer's duties according to law. The amount of the bond must be approved by the association and may not exceed $25,000. The bond must be paid for by the association. If the city or town treasurer has been elected ex officio treasurer of the association, the official bond will cover the faithful discharge of duties as the treasurer of the association.