Mo. Rev. Stat. § 262.350
The county commission of any county may, if it be deemed expedient, appropriate out of the county treasury for the benefit of any society regularly organized as a county agricultural and mechanical society, county fair, county corn growers' association, county poultry association, county stock growers' association or any other organization or incorporated society having for its object the holding of county fairs or the advancement of agriculture or its allied industries, a sum not exceeding three hundred dollars in any one year. The money so appropriated shall be drawn by the treasurer of the society on proper warrant; provided said money shall be awarded by the board of directors or other proper officials in premiums or expended by them in the purchase of premiums, to be known as "The ______ County Commission Premiums" to be awarded according to the rules, regulations and bylaws of the society; provided further, that in all counties in this state of the first class, and all counties of the second class the county commission of such county may, if it be deemed expedient, appropriate out of the surplus remaining in the county treasury, for the benefit of any such society, a sum not exceeding ten thousand dollars to be used as in this section above set out, or in any other manner that said board of directors may deem best.
§ 262.350, RSMo