Do most state parks have a 30-foot length limit?

I find Google Maps Earth view to be very useful in making such determinations. You can measure site lengths, and check out access roads for tight turns and dead ends. I am sometimes surprised at how small an area some rigs can turn around in. I watched one of the longest trailers I've ever seen make a u-turn in a Nebraska state park CG last June. I saw him come in and knew that there were no spaces open. He made it around the turn around circle and back out without a hitch, but it was a tight fit.