Well dang... I missed this thread earlier, or I would have most certainly have concurred on the 36 across Missouri route! I hate I 70 unless it's 2 - 3 am when I'm crossing there.
If you plan to ease back over the ND line to the National Grasslands for any hunting Dan, deer season opened this Friday over there, and you might want to wear Blaze Orange while in the field. Likewise, if you do, you can pick up a map of the grasslands at the ranger station in Medora. The maps show public and private land, which is a good to know where they intermingle.
Pay close attention to the weather out there Dan. I don't care if you haven't stayed in a motel in 3 years or not, if they start talking storms blowing in, go find a motel! Had one hit out there during hunting season back in the early 90s, stranded a whole bunch of folks out there in the field. Was 4 - 5 days before they got to some of them. Fortunately, it blew in opening weekend and most of the folks had enough supplies on hand to last them a few days. Although a few did get a tad chilly and a tad hungry sitting out there in their cars and campers, everyone survived as best I recall. Winter is nothing to play with out there on the plains, believe me.