Theodore Roosevelt NP

We stayed in Cottonwood and loved it, no hookups, sites are a little weird, as the road is one way, which means all the sites on the outside of the loop puts your awning next to the road, ours was on the inside of the loop. As said, some of the sites are a little on the short side, but with your 26 footer you should have no problem.
Medora is a pretty cool little town, Besides the other things mentioned, don't miss the cowboy museum.
The park has some nice hikes, wildlife include Buffalo, wild horses, deer, we even saw a Badger just before dark, plus the buffalo grazing through the campground 6' from our awning.