From RV net archives on 2WD vs 4WD..
As for rough roads, steep surfaces, loose surfaces, a 2wd truck will roll in it just like a 4wd truck. People forget that 4WD wasn't around in production vehicles until the start of World War I, and then it was special order or custom made. Before then and even after, people drove millions of 2wd vehicles around everywhere, and there wasn't paved roads in lots of areas until the 1950's. So to say that 2wd's can't go anywhere doesn't hold up. Yes people got stuck, and they winched themselves out, but to say that only a 4wd can go someplace isn't exactly true. I've driven a 2WD into some places that guys with 4WD were afraid to drive through. It depends on the driver and the level of skill and common sense they have to determine if they will get stuck or not.