Wyo. Stat. § 34-4-106
The sale shall be at public vendue, between the hour of ten (10:00) o'clock in the forenoon, and five (5:00) o'clock in the afternoon, at the front door of the courthouse, or the place of holding the district court of the county within the county in which the premises to be sold, or some part of them, are situated, and shall be made by the person appointed for that purpose in the mortgage or by the sheriff or deputy sheriff of the county, to the highest bidder. The sheriff or deputy sheriff shall not hold the sale unless the foreclosing mortgagee, judgment creditor, other foreclosing lienor or an authorized agent of the foreclosing party is present at the sale or has previously waived to the sheriff conducting the sale the right to appear and bid at the sale. The sheriff conducting the sale shall not be considered to be the authorized agent of the foreclosing party unless the foreclosing party has given the sheriff a specified opening bid to be presented by the sheriff on behalf of the foreclosing party and the sheriff actually presents the opening bid. Any foreclosure sale conducted without complying with the terms of this section is void, in which case the mortgage, power of sale, judgment or other lien which is the subject of the voided sale is not extinguished or exhausted, but may be properly foreclosed in a subsequent foreclosure sale in compliance with applicable law.
W.S. 34-4-106