A park license is not required:
(1) For any motor vehicle used on official business and owned or leased by the state or its political subdivisions or by the United States government;
(2) For commercial vehicles being used for the transportation of property or in the performance of services in the course of commerce;
(3) During a time of the year other than the park season as set by the Game, Fish and Parks Commission; or
(4) In Custer State Park, for motor vehicles engaged in through traffic using no park facilities other than traveling upon U.S. Highway 16A.