I would look into Caledonia State Park/ Michaux State Forrest. The trails there are the ultimate of the east coast, an opinon shared by Pro racer Chris Eataugh.
http://www.gettysburgbicycle.com/
That is the local shop that manages the Michaux Mega Series races. A lot of people camp at the trailhead the weekends before the races. These are appalachian mountain trails and there won't be any sizable civilization for 50 miles around in a lot of places. A great place for a race or even an epic. Do bring navigation gear as an emergency thing though. It is so big you could easily get lost. Then if you aren't riding, you can check out Gettysburg itself. A pretty town.