Missouri Revised Statutes Title XI. Education and Libraries § 177.086. Construction of facilities, sealed bids and public advertisement required, when

1. Any school district authorizing the construction of facilities which may exceed an expenditure of fifty thousand dollars shall publicly advertise, once a week for two consecutive weeks, in a newspaper of general circulation, qualified pursuant to chapter 493, located within the city in which the school district is located, or if there be no such newspaper, in a qualified newspaper of general circulation in the county, or if there be no such newspaper, in a qualified newspaper of general circulation in an adjoining county, and may advertise in business, trade, or minority newspapers, for bids on said construction.

2. No bids shall be entertained by the school district which are not made in accordance with the specifications furnished by the district and all contracts shall be let to the lowest responsible bidder complying with the terms of the letting, provided that the district shall have the right to reject any and all bids.

3. All bids must be submitted sealed and in writing, to be opened publicly at time and place of the district's choosing.