I have stayed here twice, once in the spring and once in the winter.  Both times, the main camping area was empty.  There is a large clearing off of Hidden Valley Rd (38.14822,-79.76883) just past Poor Farm Camp A Rd.  that can easily accommodate multiple vehicles with 3 or 4 fire pits.  In the spring, it is covered in wild hares.

If you follow the road further, about a quarter of a mile, is another spot for about two or three vehicles.  On the map, Hidden Valley Rd says it goes through, but the road is closed.