36 CFR §4.11

1. (a)Vehicle load, weight and size limits established by State law apply to a vehicle operated on a park road. However, the superintendent may designate more restrictive limits when appropriate for traffic safety or protection of the road surface. The superintendent may require a permit and establish conditions for the operation of a vehicle exceeding designated limits.
2. (b)The following are prohibited:
   1. (1)Operating a vehicle that exceeds a load, weight or size limit designated by the superintendent.
   2. (2)Failing to obtain a permit when required.
   3. (3)Violating a term or condition of a permit.
   4. (4)Operating a motor vehicle with an auxiliary detachable side mirror that extends more than 10 inches beyond the side fender line except when the motor vehicle is towing a second vehicle.
3. (c)Violating a term or condition of a permit may also result in the suspension or revocation of the permit by the superintendent.