Off-road vehicle enthusiasts can ride free of charge on state-designated routes and trails for a limited time later this month. The Michigan Department of Natural Resources has scheduled a free-ORV weekend for August 20-21. No ORV license or trail permit will be required on those two days, which officials say will save riders up to $36.25. The DNR designates two free-of-charge ORV weekends each year. Officials say the policy is meant to encourage riders to buy a license and trail permit for use during the rest of the year on the 3,800-mile ORV trail network. Fees collected from riders are used for trail expansion, maintenance and upgrades, as well as law enforcement and fixing damage from illegal use.