Even at the Glendale site, any trailers left unattended will be subjected to moving or even stolen. Even with a hitch lock. I have personally seen this many times through the years leaving a boat trailer at Glendale, WAM, Dave's Motorboat Shop and Alton to name a few. It is almost a fact of living up here. The most bizarre incident was when someone swap my trailer for another same model trailer with defective brakes and tires. The local police did a TIN research and the trailer was stolen from the cape! My trailer never showed up in the database.
So expect the event that your trailer may not be there