The 12 to 18 trailer sites usually have trees or rock(s) limiting maneuvering into the space, but sometimes they have a short paved area. Also many of the sites have a good sized concrete curb at the back. Unless you have high ground clearance the back end might not go over it. I camped many times with a 21 ft travel trailer towed by a Ford Explorer. There is no way I would try to back it into those small sites. I've even had trouble trying to park the Explorer off the road in the 35 foot sites. If anything sticks out into the road you will be asked to move it or leave. If you don't fit into the site you reserved, they will not give you a different one.
