There has been, may still be, a road atlas for RV folk. I last bought one in 2005 or 2006 (it is undated).
This is the "Road Atlas RV & Camping Edition" published by National Geographic, which lists, describes, and locates RV parks, campgrounds (not the same thing), national and state parks. The number of listings is quite small, compared to the commercial RV park and camping guides like Trailer Life. I got the atlas in a National Geographic Map Store, don't remember whether it was Chicago or Houston.
I also have the Rand McNally Motor Carrier's Road Atlas. With that, I've always carried either Trailer Life or Woodall's RV and camping guide. I now use it with the Good Sam's guide, which combines the two.
Of the two, I think the MCRA is the better road atlas for planning RV trips. The RV and Camping road atlas simple does not have enough listings, and detailed enough listings, to be useful. An atlas with enough listings would be three or four inches thick, to unwieldy to use as a road atlas. The National Geographic Road Atlas also lacks information about the designated highways, and clearance and weight limits, which can be important to those with larger RVs.
With a good wireless data connection, you can find your map information and RV park or camping information online, maybe more readily than paging through a guide. But the guide on paper was really useful, when DW was still alive to look things up while I was driving, and make calls to RV parks about space availability as we were approaching our evening stops.