Mo. Rev. Stat. § 226.690
Any junkyard lawfully in existence on August 4, 1966, which is within one thousand feet of the nearest edge of the right-of-way and visible from the traveled roadway of any highway on the interstate or primary system shall be screened, if feasible, by the state highways and transportation commission so as to render it not visible from such highways. When the state highways and transportation commission shall determine that adequate screening of such junkyards is not economically feasible or possible, it is authorized to acquire by purchase, exchange, condemnation proceedings, or otherwise, all interests in land necessary to secure the relocation, removal, or disposal of junkyards involved and to pay for the relocation, removal, or disposal thereof. The commission may acquire such lands or interests in lands as is necessary to provide adequate screening of junkyards when it considers it to be in the best interest of the state.
§ 226.690, RSMo