I've been a road biker for years. But I've just bought a Rockhopper, and have been exploring desert trails where I live (The high desert, near Mojave, CA). Sometimes the trails get so sandy I have to go around them in order to keep riding--and that's with Fat, IRC Trail Bear tires at low pressure. I'm not interested in making new trails or going wildly off into the desert. But I do feel a little guilty when I leave the trail for a few minutes.
I could see how tearing up the desert with high impact, off road vehicles could be harmful, but what about bicycles. Also, I weigh 143 lbs. What do you think?