Mo. Rev. Stat. § 51.122
The clerk of the county commission of each county of the second, third or fourth class shall assist in the preparation of gas tax refund forms when requested by residents of the county, and shall file an annual report with the county commission on or before December thirty-first of each year of all federal revenue funds received from any federal agency of the United States during such year and file a copy of any other reports with the county commission required to be filed with any federal agency necessary for the county or county commission to receive any federal revenue sharing funds, or any other federal funds from the United States government or any agency thereof; provided, however, that sections 51.122 and 51.305 shall not apply to any county of the second class which has an assessed valuation in excess of three hundred million dollars on August 13, 1974.
§ 51.122, RSMo