How big of a 5th wheel toy hauler can you get in the wash areas?

Its all about your driving skills.  There are some huge rigs out there, motorhomes, cars, etc.... .  One of my buddies has a 52ft triple axle race trailer he brings out with his stock Chevy 2500 with highway tires.  He doesn't air down.  Large rigs out there just need to go down Wash road and have somebody that arrived before them guide them in.  Its not usually an issue.  Lots of people out there that can give you a pull if you get stuck.  Last Thanksgiving I pulled out 2 motorhome with trailers when we found some soft stuff.

If your worried you can park closer to the road.  The further back to the dunes you go, the softer the sand gets.