I stayed in Grant Village. Got a campsite right on Yellowstone Lake. It was beautiful & inexpensive. However, no hook-ups.
My trip took me from Jackson Hole, WY. , through Grand Teton NP. I stopped at a campground (with a large hotel) just outside the South Gate of Yellowstone. Their prices were 'very expensive' & the campground was pretty much a piece of dirt with a picnic table. You had to go into the hotel to pay but, I asked to see the campsite before paying. After seeing what I was going to get for my money, I left (ANGRY!!!!!).
From there, I headed into the Park & while at the gate, asked about availability of camping, in the Park. The, very nice, young woman at the gate, sensing my anger, told me that there were vacancies at Grants Village & sent me there. It turned out to be a great experience at a reasonable price.
Joe F. (Buffalo)