Hmmm - we do have a night where we aren't booked for overnight. So if we left Yellowstone around 1 (earlier? later?) is it feasible to drive beartooth/chief Joseph and then stay at Cody...then drive to SD the next day?

I think leaving at 1 p.m. would be fine and give you enough time to enjoy the scenic roads and a night in Cody. The next day to SD is totally doable. The only caveat would be if you wanted to see Devil's Tower that day. Not sure how out of the way that is.

You have two unspecified nights in Idaho and only one night in Jackson Hole. I think your boys, especially, would like Jackson. Scenery is stunning. Fun Old West style town. I'd spend two or three nights there.

We live in Colorado and were disappointed in South Dakota. I would take at least one night from there, and add it to the spectacular areas of Jackson and Yellowstone. They are like nowhere else.
And you get to stay in Old Faithful Lodge. Well done!

Speaking of Red Lodge and Cody, there's a nice, family-owned guest ranch in that area. Horses and fishing and cabins and relaxing and scenery:

http://www.kbarzguestranch.com

Your teens might like it a lot.

We're returning here http://www.redfishlake.com/ on our way to Yellowstone this fall. The area between Ketchum and Stanley is just gorgeous.

Thanks for all of the information! Unfortunately I now have a problem - starting a separate thread hoping to resolve!