An estimated 200,000 people a year flock to the desert valley for recreational pursuits: hiking, camping, rock-hounding, star-gazing and a new sport called "geocaching," a treasure hunt using GPS technology. Moviemakers use the desert floor for chase scenes.

But the valley has gained its greatest acclaim in recent years as an untamed, unregulated venue for off-road vehicles. Off-roaders take their Jeeps, motorcycles, dune buggies, ATVs, "rock crawlers" and other souped-up vehicles over, around and through the rills and hills and rocks.