Mo. Rev. Stat. § 162.071: Annexation of district to adjoining district, when — state board of education, duties.

When the creation of a school district or a change in the boundaries of an existing school district leaves the remaining part of a district containing less than twenty children of school age or when the remaining part of a district is left without a schoolhouse, the state board of education shall order its annexation to an adjoining district. The annexed territory shall become a part of the receiving district on receipt by the secretary or clerk of the district of notice of annexation from the state board of education.