I'm not from the area, but I have found Google maps/Google Earth very helpful.
Start by looking at areas that look interesting. Study the maps, and bring the person icon down to the streetview. Often times you can find two tracks and forest roads that are not on the map. Plus if you have any national forests nearby, you can ride you plated dirtbike on the NFS fire roads which is my personal favorite.
Some emaples of NFS fire roads here in Michigan.
