Mont. Code Ann. § 76-2-307

In order to avail itself of the powers conferred by this part, except 76-2-306, the city or town council or other legislative body shall appoint a commission, to be known as the zoning commission, to recommend the boundaries of the various original districts and appropriate regulations to be enforced therein. Such commission shall make a preliminary report and hold public hearings thereon before submitting its final report, and such city or town council or other legislative body shall not hold its public hearings or take action until it has received the final report of such commission.