Regarding Teton - we stayed at Coulter Bay in 2006 with our 28' rig, and it was tight. Diesel was $5/gal at the park station.
In Yellowstone, we stated at Fishing Bridge. A little tight, but a good base of operations to tour Yellowstone.
Someone else asked about Mt. Rushmore in S. Dakota - Big Pine Campground
which is a little west of Custer, or Custer State Park. We stayed at Big Pine in Sept '07.
Big Bad Wolf - '15 Dodge Ram 2500HD 6.7 CTD / Reese 15k Pro
Wolf Den 3 - '14 Rockwood Signature Ultra Light 8280WS
Nights camped 2015: 25