Everytime we have stayed at state parks here in Washington, it's a gamble getting a space, and if you do, don't leave it for a second, especially to go get you'r RV, people dont have the same respect for "I was here first", and I can also remember when you could leave your chairs and ice chest just sitting along side your rig, no one would bother them.
We were parked at one park close to a big city, when a couple came in and set up thier camp,tent,chairs and such, then left, the ranger was patroling the area and saw a couple of "Early Twentys" removing the gear so they could camp there, he did his job and ran them off, later in the evening all of thier gear was found piled on the tent and the whole thing was on fire.