Mo. Rev. Stat. § 65.010

There is hereby provided an alternative form of county government for counties of the third and fourth classes as authorized under the provisions of Section 9, Article VI of the Constitution of Missouri, 1945, to be known as the "township organization" form of county government. Any county of the third and fourth class in this state may adopt this alternative form of county government in the manner provided in sections 65.010 to 65.050.