Idaho Code § 40-617

Commissioners shall, at least three (3) weeks prior to their regular meeting in October or March, or at other times as may become necessary, cause notice to be published in a newspaper, published in the county, for sealed bids to be received by the commissioners for the repair and improvement of the highways in the county highway system. Each proposal or bid submitted to the commissioners, shall be accompanied by a bond conditioned for the faithful performance of the duties of the contract, which may be entered into by and between the party making the proposal, or bid, and the commissioners.