Wyo. Stat. § 11-20-221: Common carriers not to receive livestock for transportation without certificate.

Except as otherwise provided, it is unlawful for any railroad, trucker or other common or contract carrier, or any person to receive for transportation or to transport any horses, mules, cattle or sheep from any county in Wyoming to any other county, state, territory or country, until furnished with an official certificate of inspection, filled out and signed by an authorized inspector, showing the horses, mules, cattle or sheep to be transported have been inspected for brands and ownership.