If you visit Maryland State Parks often, you can save money by purchasing the 2010 Maryland State Park Passport. It costs $75 for Maryland residents or $100 for out-of-staters and may be ordered online.
The pass offers unlimited day-use entry for everyone in a vehicle (up to 10 people) to Maryland's state parks and Cedarville State Forest, unlimited boat launching at most facilities, and a 10 percent discount on state-operated concessions and boat rentals.
For parks with honor box systems, the pass covers entry service charges. The 2010 Passport expires December 31, 2010. Order your pass here.