Mont. Code Ann. § 35-18-205

A cooperative may, without amending its articles of incorporation, upon authorization of its board of trustees, change the location of its principal office by filing a certificate of change of principal office executed by its president or vice-president, under its seal attested by its secretary, in the office of the secretary of state and also in each county office in which its articles of incorporation or any prior certificate of change of principal office of such cooperative has been filed and paying the fees prescribed in this chapter in connection therewith. Such cooperative shall also, within 30 days after the filing of such certificate of change of principal office in any county office, file therein certified copies of its articles of incorporation and all amendments thereto, if not already on file therein.