We made a decision to camp on the eve of a potential blizzard. The grounds have sites in close proximity to a toilet without running water. When we arrived, half of the sites were occupied, but only a few left notes on the board as was requested by the service. We were pulling a 15' trailer and could only access the sites from driving reverse along the one way road. The trailer barely fit the back-in site and we were able to detach and park our vehicle perpendicular to the trailer. It was perfect for our set up, but I wouldn't recommend anything larger than 15'.