The Cabela's in Sidney, NE has a real RV park. W,E, and dump station. Private, lockable bathrooms with showers that are cleaned after each use. The Sidney store is the Flagship.
On one visit, I was talking to the guy at the door. Turns out, he was one of the originals. Their first location was on the second floor of a building in downtown Sidney. Mail order only. He told me how to find it. "Second floor of a building with a brown outside door on the second floor. A bunch of holes in it where we used to shoot arrows into it when we were bored." He wasn't kidding.