If you look at this old thread of mine, you can find a lot of maps that show back and forest service roads.
http://www.bikepacking.net/forum/bikepacking/a-good-resource/I've been looking for tour divide type of roads for training and these have been very useful. I'd love to investigate some N.C. roads around Pisgah, and the Blue Ridge areas. What I do is, when I find a good looking prospective area, I print out the PDF in a 3x3 matrix and tape it together for a higher resolution map. The maps are usually GPS tagged so that you can get a LAT/LON fix from the mouse cursor. I then often tape a few maps together and get a much better view of the roads and trails that are available.