The problem with using the Truckers Atlas is it doesn't list all the side and back-roads, ie like the one that leads to that obscure campground you are going to for the first time.
If you use a GPS, there is a firm selling a POI file for it that lists all known (something like 50,000) low clearance (below 14 ft) locations in North America. See
hereAs for utility lines, they are all
supposed to be high enough (14 ft) to allow the clearance of legal vehicles, at all times and in all locations. This allows things like say, moving trucks, to move about and load/unload households.