Mont. Code Ann. § 35-16-205

Within 30 days after the issuance of a certificate of incorporation, the persons named and designated in the petition to be directors or trustees for the first 3 months shall cause a written notice to be mailed or delivered to each and every signer of the petition of a proposed first meeting of said corporation or district for the purpose of adopting a common seal, adopting bylaws, and providing for the issuance of stock or other evidences of membership of the members thereof and for the transaction of such other business as may properly come before a meeting of the stockholders or members of a corporation or district formed for the purposes named in the petition.