Visitors to Wyoming can find numerous RV campgrounds close to Yellowstone National Park, not to mention a number of campsites available directly within the park. Due to the popularity of the park — especially during the summer — visitors should consider reserving a site in advance. Planning aside, Yellowstone offers visitors beautiful vistas and a wide variety of recreational opportunities. However, size restrictions do differ from site to site.
Camping (w/electric hookup) Grand Teton & Yellowstone area - Grand Teton National Park Forum
Yellowstone RV Camping | RV Camping
If you are going "glamping" in Yellowstone, this is your on option for full hook-ups--sewer, water and 50 amp power. This village has a store, fuel, propane, RV repair and great shower facilities. Fishing Bridge is central to the entire park, so a great jumping off point. Exceedingly quiet. We wanted full hookups, because we were staying 8 nights. The hookups were fine, but the sites are so close together, I could hear the people walking in the next rig!
The Best RV Camping Locations - Nationwide
Other campgrounds in the park have no facilities. One day for each? You can drive through Grand Teton NP, but there is quite a bit to see and to do beyond just looking at the incredibly beautiful vistas. YNP needs at the very least two full days.
RV at Yellowstone's Madison Campground. Photo by NPS. Driving an RV can feel like riding on the back of an enormous dinosaur when you are traveling on narrow mountainous roads. There are safer, alternate roads to get you where you need to go.