To anyone that's interested in offroading and its impact on the environment, please see :Tread Lightly. It's a nonprofit organization spearheaded by a bunch of sensible off roaders.
By no means am I saying don't off road, instead, I'm asking you do so without causing any damage to the earth. Doing donuts, ripping apart wet soil, and causing erosion isn't very responsible.
Voyager, have a look at any of these brochures.