Wyo. Stat. Ann. § 24-5-118

The transportation commission shall set aside and appropriate out of funds in their possession or under their control, not otherwise appropriated, the sum of four million dollars ($4,000,000.00) at the beginning of each biennium to be placed in an account known as the industrial road program account within the highway fund. All funds not used during each biennium shall lapse and be returned to the general account of the highway fund.