IMO the NPS map and the Trails Illustrated maps are both essential when on the backroads in BIBE. NPS list everything and we mark where we saw various things on it, but the Trails Illustrated is more detailed for navigating and precise location of things. While the GPS is nice, I consider a good map and compass as indispensable. USGS quad maps are probably the best, but when driving the backcountry roads, you can buzz thru one quad pretty quick (I've found for most of my off road driving here I use the USGS 100K maps more than the 24K maps unless it is a short trail).
I believe the Trails Illustrated does show all the backcountry road campsites, but don't have ours with me now to check.
Robert