Mo. Rev. Stat. § 226.760

The state highways and transportation commission may acquire such areas in fee, easement, or other interest as may be determined by the commission to be reasonably necessary to accomplish the purposes of sections 226.750 to 226.790. The acquisition may be by gift, purchase, exchange, or condemnation, and if the latter be necessary, it shall be carried out in the same manner as now provided by law for acquisition of right-of-way for state highways.