For six years, Duane Zavadil has been a frequent visitor to what is sometimes called the world’s longest art gallery: mile upon mile of Native American etchings carved as many as 2,000 years ago on the enormous sandstone rocks of Utah’s Nine Mile Canyon. But he’s not here for the drawings of buffalo, bighorn sheep and hunters with their bows and arrows. Zavadil works for Bill Barrett Corporation as the natural gas producer’s vice-president for government and regulatory affairs. That makes him the man responsible for battling the company’s local adversaries – people who oppose what they fear will be irresponsible gas production in this remote, rugged archaeological treasure trove.

Bill Barrett puts this area at risk, according to the company’s critics, and not just at the 800 points where it wants to drill wells. Dozens of tankers carrying water and carbon dioxide, pick-up trucks and rigs daily traverse the small dirt road winding through the canyon. The dust clouds that follow in the wake of the trucks are so thick the road becomes invisible for minutes after they pass. And when the dust settles, it coats the pictographs (drawings) and petroglyphs (etchings) with magnesium chloride – which Bill Barrett has been spraying on the road to absorb water and limit the dust. The substance is a salt, and archaeologists fear that it may be damaging the art.