Idaho Code § 42-2004

A certified check for a sum not less than $250 nor more than $2500, as may be determined by the rules of the department, shall accompany each request and proposal, the same to be held as a guaranty of the execution of the contract with the state, in accordance with its terms, by the party submitting such proposal, in case of the approval of the same and the selection of the land by the department, and to be forfeited to the state in case of failure of said parties to enter into a contract with the state in accordance with the provisions of this chapter.