Mont. Code Ann. § 35-2-229

If a corporation does not have members, its incorporators, until directors have been chosen, and later its board of directors may adopt one or more amendments to the corporation's bylaws subject to any approval required pursuant to 35-2-232. The corporation shall provide notice of any meeting of directors at which an amendment is to be approved. The notice must be in accordance with 35-2-429 (3). The notice must also state that the purpose or one of the purposes of the meeting is to consider a proposed amendment to the bylaws and contain or be accompanied by a copy or summary of the amendment or state the general nature of the amendment. The amendment must be approved by a majority of the directors in office at the time the amendment is adopted.