Trailer sizing in Yellowstone, other NP sites

Flagg Ranch CG is located just 8 miles south of the South entrance between GT and YS. It has full hook ups. We spent 6 days there last summer. My suggestion is that because the most animal action takes place between sunrise and 9:00 AM and just before sunset when the animals come out of the trees, get up early and beat the crowds. Most visitors sleep late and congregate around the geysers and trails during the late morning and mid afternoon when the traffic starts to back up. Each day we picked a certain area of the park to visit for the day, then got up early, drove with little traffic to that area, spent the day and then drove back in time to have a little time around a fire. Also check the Ranger talk times and try to attend them. The park is HUGE, so plan your time.