Wyo. Stat. § 24-1-104: Management and control of county roads.

All county roads shall be under the supervision, management and control of the board of the county commissioners of the county wherein such roads are located, and no county road shall hereafter be established, altered or vacated in any county in this state, except by authority of the board of the county commissioners of the county wherein such road is located, except as is otherwise provided by law.