Biggest hinderance is the locale you are in. Not much of exporation in that neighborhood. You need to move from the metro area. I moved about 10yrs ago and stopped in KC. A lot better but not completely exploration wise. But I'm 10 hrs from Denver and under 20 from UT which as lots and lots of backroads through legal land.
If you like the exploring aspect with camping, check out Big Dogs. They had in the past an exploration style trailride with camping. It was in PA so I'm not sure what they do now (that was over 10 yrs ago).
Have you checked with your local 4wd clubs in the area? They probably visit GWNF for a trip or 2 a year, may hit the ORV parks in PA. You could join up and get an understanding of the wheeling environment. Many clubs travel on Friday, setup camp, wheel on Sat, camp, then wheel little more Sunday morning before breaking camp and heading home.
Since you are in northern VA, check out the VA beach (Chincotique?sp?) where the wild horses roam freely.