Mo. Rev. Stat. § 66.707: Constitution certificates as ratified to be filed where.

Duplicate certificates shall be made, setting forth the county constitution adopted and its ratification, signed by the election authority of the county after canvassing election returns. One of such certified copies shall be deposited in the office of the secretary of state and the other, after being recorded in the records of the county, shall be deposited among the archives of the county and all courts shall take judicial notice thereof. This section shall also apply to any amendment to the county constitution.