Wyoming has adopted 390.21 of the Federal Motor Carrier Safety Regulations (FMCSRs).
Section 390.21 applies to intrastate operation of any vehicle engaged in transporting of persons or property, having a gross vehicle weight rating, gross combination weight rating, gross vehicle weight, or gross combination weight of 26,001 pounds or more, or a vehicle of any size transporting a placardable amount of hazardous materials.
All commercial vehicles operating solely in intrastate transportation must display their USDOT number followed by “WY” on all vehicles.
Example: US DOT 123456 WY