Mo. Rev. Stat. § 262.510

The county commission in every such county shall apportion the proceeds of the levy made pursuant to section 262.500, and in accordance with the provisions of section 262.500, among the several objects and subjects in section 262.500 mentioned, and offer suitable premiums in each class thereof to the full amount available from the levy. All such premiums shall be offered for exhibits made at public fairs held in the county. The exhibits shall be in place at the fair at least twenty-four hours before the opening thereof to the public, and remain in place until midnight of the last day of the fair.