We were there last year and they were pretty insistent when we tried to make reservations. We did not stay there but went through the campground and there were units that were longer so I guess it depends on who is there when you get there. We did stay in a Forest Service CG just outside of the west entrance which was quite nice and some of the sites had electric which was nice as we had seven inches of snow one morning when we woke up. There were several large sites in the Forest Service CG, I believe the name was Bakers's Hole, it was right on the Madison river where it flows out of the park.