The Mysterious Devices Speeding Mining Exploration in Utah

Bushwhacking through a stand of stunted aspens above 10,000 feet in Utah’s Tushar mountain range, the mountain guide Trevor Katz held his Garmin to the sky and pointed it south. “We should just look for an opening,” he said, glancing over at his colleague, Bailey Pugh, from under a ball cap he’d cut into a visor.

He took a few steps steeply uphill, then down, careful not to slide on the scree. “It says it’s right below us, by probably 10 meters. Wait, five.”

Wading through walls of branches...