My search for the "Falling Man" pictograph takes me to Nevada's Gold Butte Wilderness, where I meet three of the system's most impassioned local supporters: Nancy Hall, a former casino waitress from nearby Mesquite, and a retired couple, Roy and Betsy Miller. They are the heart of the Friends of Gold Butte, formed to push for federal protection of this 300,000-acre stretch of desert that was home to 2,000 rugged souls at the turn of the last century but has long been abandoned to their ghosts.

An hour east of downtown Las Vegas, the now-stalled carpet of homes ends and the desert rolls uninterrupted into the mountains. We tool over a rutted, boulder-strewn, axle-breaking road. An hour later, the road peters out and we park in the sand. After a short hike through rock-cobbled desert studded with Joshua trees, we enter a small canyon with red, brown, and gold walls. I'm pleasantly surprised to realize that I am standing in an aboriginal art galley. Scratched and pecked into the desert varnish, the dark mineral patina that covers the walls, are mysterious symbols left by people who lived here a thousand years ago—spirals and arrows and figures of humans, usually in panels with dozens of other figures. One rock, called Newspaper Rock, has hundreds of different symbols etched into it. No one really knows what they mean, but guesses range from art created in trance states to news of the day's events. We clamber along a circuitous, precipitous route across a rock face to a small saddle of smooth, rounded stone. Through a hole in the rock, a circle of blue sky beckons. I bend down, crawl through, and head down a trail. In the middle of a wall the color of an Irish setter is a beguiling stick figure in motion, a realistic depiction of a man hurtling backward toward the ground.

"No one knows what it means," says Roy Miller. "Did someone fall?" It is a mystery that will likely remain a mystery.

These three desert rats are what Norton and Babbitt have in mind for their Friends Groups. And we run into more friends. On our way into Gold Butte, we stop and chat with a carload of people who are "site stewards." Trained by the BLM and committed to protecting artifacts, these volunteers prowl the desert, watching over the petroglyphs and looking for damage, alerting the BLM if they see any suspicious activity, filling in the gaps created by federal underfunding. (There is only one BLM law enforcement agent for this expansive stretch of desert.)

Some locals who have used this landscape as they please for a long time—to ride off-road vehicles or graze cattle, for instance—aren't happy with the new protections, which involve trail closings and the posting of notices by BLM staffers to reassert ownership. Some signs have been chain-sawed down; others have been filled with bullet holes. "There haven't been any confrontations out there, but we have to be careful," says Gail Marrs-Smith, who manages the area for the BLM. "We travel in pairs."