Sounds like a wonderful trip. I might be able to use some of this information as we are planning on a Maryland to Grand Canyon trip next summer.
We did the Maryland to Yellowstone through Mt Rushmore and the Badlands trip in our high wall popup 5 years ago - loved the trip, all the sights were so awesome. Since we only had two weeks for our trip, we choose to use the KOA campgrounds throughout. Of the 10 KOAs we stayed at, only two were for more than a single night, so this worked for us though I would have loved to be able to use more state and federal parks and stay several days at each place. With the pace we had, it really was not camping, it was more like pulling your bed along. We only used the campground as a base and spent all of our time sightseeing, would get back to the camper, eat go to bed to start all over the next day.... we did not even set out the camp chairs. I imagine our Grand Canyon trip will be similar, but we are so looking forward to it.
HTT: "EscapeII" 2016 Shamrock 23WS (current)
PUP: "Escape" 2010 Rockwood HW 277 (gone)
TV: "Bruce" 2011 Dodge Durango V8 Hemi Crew
Just us gals (me, Sis and our daughters)
Traveled 19520 miles and 209 nights in 7 years and counting