Mont. Code Ann. § 33-4-301

Upon commencement of the legal existence of an insurer, its initial board of directors shall adopt such original bylaws, not inconsistent with the state constitution or this chapter, as may be deemed necessary for the management of its affairs. The bylaws shall be subject to the approval of the insurer's members at their next succeeding meeting. The members shall otherwise have the power to make, modify, and revoke bylaws.