Wyo. Stat. § 22-25-115
Except as provided herein, written campaign advertising shall not be placed on or attached to any real or personal property of the state or its political subdivisions. This prohibition shall not apply to fairgrounds of the Wyoming state fair or of any county fair organized under the laws of this state. The University of Wyoming, any community college and school district may permit such advertising subject to regulation by their governing board as to time, place and manner. Any rules and regulations adopted shall provide for equal access to opposing political views. Subject to the approval of the landowner and any rules and regulations adopted by a municipality, campaign materials may be placed on municipal street rights-of-way. The department of transportation shall allow campaign materials to be placed on a state right-of-way within a municipality to the same extent which the municipality allows campaign materials to be placed on municipal street rights-of-way. Nothing in this section shall apply to any interstate highway.
W.S. 22-25-115