We are on a similar trip. To get around Chicago I took RT 30 to RT 80 on a Saturday morning little traffic and no tolls. Mount Rushmore was nice at night also save your parking ticket from the day time to get back in. Devils Tower had a great NP campground with a view of the tower. Badlands was nice saw a lot of animals Big horn sheep, mtn goats, buffalo, and my GS got to feed the prairie dogs. Yellow stone was a zoo very crowded only stayed inside one night. Could not find parking at a lot of the popular places during the day. We stayed in a NF CG outside the park and drove in either early in the morning or late in the afternoon. Saw 9 bears on the drive to Lamar valley late one after noon, 2 black bears with cubs, 2 cinnamon black bears and one grizzly. Lots of elk and buffalo. No problem of getting a CG in Tetons NP. Flaming gorge was beautiful, the lower part had cleaner water. Stayed at fire hole CG at the top, wish I would have stay one night at the bottom but made reservations for the 4th of July weekend at Wolford CG in Colorado. Caught some nice trout and Kokanee salmon in the reservoir there. Will start to head home tomorrow. Enjoy your trip.