We just left Yellowstone on Wednesday, very busy this time of year. I would not go if I didn't have reservations. We spent 3 nights at the North Entrance in Gardiner, MT at Rocky Mountain RV; 3 nights in West Yellowstone at Grizzly RV Park. It was very nice! 3 nights at Colter Bay RV in Grand Teton National Park. Made all reservations in January. Every campground we passed in the last two weeks said "FULL."
We were there last week, and everything was picked. I made our Fishing Bridge reservations in January. I'm so glad we made the decision to town my Jeep, because even though the motorhome is small, no way could we have parked at most of the sight seeing locations. It was just too crowded.