There should be some CG's open inside Teddy Roosevelt NP, depends on how soon you're heading that way. And there is a commercial RV park in Rugby ND in the nothern part of the state, east of Minot. Get hold of tourism folks in ND and see what CG's you may be interested in, sightseeing adventures and then plot your travels from there. Lots of traffic in the Sidney MT and Williston ND areas but the highways are excellent so there's nothing to worry about as far as trucks are concerned, and seems it's only about 100 miles or so of oil field activity.
