Mo. Rev. Stat. § 245.370: Work to be let to lowest bidder.

If it shall be decided at said meeting in the manner aforesaid, to do said work, the directors shall proceed to let the same out to the lowest and best bidder; provided, however, that said directors shall have the right to reject all bids, if the same be deemed too high. No director shall, either directly or indirectly, become a contractor for the building or repairing of any levee or public work contemplated by sections 245.285 to 245.545, nor have any interest therein, present or remote; and any director so offending shall, upon conviction, be punished by imprisonment in the penitentiary not exceeding five years.