In 13 years of fulltiming, we've only arrived at our site once to find another RV parked on it. That time, the RV owner quickly hopped out and explained they were all loaded up and ready to go, but his wife had a last minute bathroom emergency due to a stomach bug of some sort. A couple of minutes later she showed up, and they were on their way. Not a problem, just a case of them being a few minutes late for a 1 PM checkout when we were right on time for the 1 PM check in. If we had been just a few minutes later we never would have known. The only other time our site was occupied and the office directed us to another site temporarily was when our site was "occupied" by a burned out TT surrounded by crime scene tape. It seems a fellow had killed his wife and tried to destroy the evidence by burning the trailer. Three days later the site had been cleaned up and we were allowed to move in to it. The temporary site they gave us was in the work campers village that wasn't in the nicest part of the park, so we were happy to move.