Mo. Rev. Stat. § 234.210

Any county, municipality, road district, political or civil subdivision of a county or of the state, severally or acting with other authorized agencies in this or adjoining states, may acquire, own and operate, construct, or aid in the construction, in whole or in part, improve or extend, and maintain toll bridges, including the approaches thereto, either within or adjacent to the territory over which such public agency has jurisdiction and over any of the rivers and waters in or forming the boundary between this and other states.