Mo. Rev. Stat. § 251.370

Any local governmental unit within the region may adopt all or any portion of the plans and other programs prepared and adopted by the regional planning commission. Before the adoption, amendment or extension of the plan or portion thereof, the governing body of any political subdivision shall hold at least one public hearing thereon, fifteen days' notice of the time and place of which shall be published in at least one newspaper having general circulation within the political subdivision, and/or notice of such hearing shall be given the state office and shall be posted at least fifteen days in advance thereof in at least three conspicuous public places within the political subdivision.