We were there in mid May. We stayed in Madison because it was one of 3 open and was centrally located. It was decent but there was no privacy between sites. And, there are no services there. Mammoth Hot Springs is in the northwest corner of the park.It appeared to have more privacy than Madison and there are services in Mammoth ,gas, food and things to see. Plus you are about 5 miles from Gardiner ,Mt where there is also gas, a grocery store and several restaurants.So maybe split your time between the 2. I would also recommend eating at the Old Faithful Inn.Beautiful building and good food. Meals from about $12 to $30.