George Washington national forest has a few trails. I'm in fairfax and there's nothing around here but some power line trails and some back roads. Everything else that was accessible (near AOL in Dulles) has been bouldered, treed, or poled shut.
There's a lot of good places if you ever head down to SWVA. You can check out Jeep Forum - Jeep Enthusiast Network as there's plenty of members from this area that can help you out. There's a lot of good old deserted logging roads around here and old abandoned fire towers as well. North East TN has a ton too!!
I live down in the Christiansburg area and about the only legal decent place near here is Potts Mtn. I ride with the scc4x4 guys every now and then and they are a good bunch. One of my favorite places is Big Dogs up in Gore (near Winchester). It is on private land but they hold several events a year that are open to the public. It can be a bit pricey but the wheeling is WELL worh the price of admission. Everything from mild to wild. I also really like crozet and uwharrie.