Mo. Rev. Stat. § 290.325

No public body, officer, official, member, agent or representative thereof authorized to contract for public works shall award a contract for the construction of such improvement or disburse any funds on account of the construction of such public improvement, unless such public body has first had the department determine the rates of wages required to be paid in the locality where the work is to be performed and such determination has been made a part of the specifications and contract for such public works.