In WA state in Ocean Shores, you can drive on the beach.. You can't 'camp' or overnight there, but you can bring your rig on the sand...
All the soft sand is above the high tide level... That's where everyone gets stuck at least at Ocean Shores, WA.. :)
I've pulled out many small cars and 2wd trucks in my time going there with just a stock 4x4 F150..
I don't go into the soft sand like those stuck were in..
I have seen RV's out there, but they seem to stick to the hard packed side and move accordingly as the tide comes in and then leave when it gets too close.
I don't go out there anymore, as just way too many 'goofs' out there now... But, back in the day, it was fun and a family could enjoy themselves and not have to deal with all the ATV's and other such nonsense..
Ooops... Too many cold snacks I think... :)