Mont. Code Ann. § 35-20-203

All vacancies occurring by death or otherwise in the membership of any cemetery association organized under this chapter shall be filled by a vote of the surviving or remaining associates named in the certificate of association. All persons so elected to fill any such vacancy shall be entitled to vote at the election of trustees and be eligible to the office of trustee of said incorporation and shall have and be entitled to the same rights, powers, and privileges as the original associates named in said certificate.