Yellowstone ??????

It depends on what type of "camping" you like. Some here will say that there are CG's within YNP that will accommodate your rig and trailer but I would have to disagree, with the exception of Bridge Bay. They have large sites up front and a huge parking lot that you may be able to park your trailer in. When we go over, we stay in West Yellowstone and since we prefer CG's, we stay at Baker's Hole, a FS CG 2 miles north of West Yellowstone. They have sites that you will fit in and you can make the turns. There are quite a few pull throughs and most sites have electricity. There is a water fill station at the entrance plus numerous spigots throughout. If you like RV parks, Grizzly RV in West Yellowstone is a super nice place. We've stayed there for a couple of nights either coming or going to dump our tanks, do laundry, and refill. Most sites are pull throughs. The service is super. Free coffee every morning at the clubhouse and within walking distance of town. Another place we've staying within driving distance of YNP is at Colter Bay RV park. Most sites are pull throughs and full hookups. They also have a dry CG side. We've stayed at Flagg Ranch too but that was years ago so I couldn't tell you how it would be for a rig your size.