Mo. Rev. Stat. § 229.300
In all counties of class one it shall be unlawful for any person, firm, association or corporation to excavate or encroach on, or cause to be excavated or encroached on, or to lay, locate, erect, remove or maintain any conduits, poles, pole lines, wires, mains, pipes, conductors, sewers, tramways or drains, within, upon or across the right-of-way of any street, avenue, boulevard, road, alley, public easement, or highway outside the city limits of any municipality in such county; or to move upon, over or across any such street, avenue, boulevard, road, alley, public easement or highway, any building, house or other structure, or to operate or cause to be operated, on any such street, avenue, boulevard, road, alley, public easement or highway, any vehicle, or combination of any vehicle or house, building or other structure, which exceeds the limits of length, width, height, or weight as set forth by the regulations of the Missouri state highways and transportation commission governing such on state highways, without first having obtained a written permit, denominated as a special use permit, from the county highway engineer and surveyor.
§ 229.300, RSMo
RSMo 1939 § 8647, A.L. 1945 p. 1489