The contract shall be signed by the successful bidder and returned, together with the contract bond, within twenty (20) days after the contract has been returned to the bidder. If the contract is not executed by the Department and approved within fifteen (15) days following receipt from the bidder of the signed contracts and bonds, the bidder shall have the right to withdraw his bid without penalty. No contract shall be considered effective until it has been fully executed by all the parties thereto.
045-8 Wyo. Code R. § 8-6