Wyo. Stat. § 9-4-812

The state treasurer or his authorized deputy may withdraw any and all funds deposited for the purpose of paying the appropriations and obligations of the state as lawfully required or whenever he deems it advisable or to the interests of the state to do so except funds deposited as time deposit, open account shall require notice in advance of withdrawal as specified in W.S. 9-4-809. The state treasurer and his sureties are responsible for the faithful performance of the duties of the treasurer under the law, and for a proper accounting and turning over to his successor of all monies paid to the treasurer as such but he shall not be held personally liable for any monies that may be lost by reason of the failure or insolvency of any bank or credit union selected as a state depository nor for the deficiency or loss upon any surety bond or securities deposited by any bank or credit union, if the surety bond or securities were placed according to law, unless the loss could have been avoided by the exercise of reasonable care and diligence on the part of the treasurer or his deputy, in which case the treasurer is liable to the state for the loss.