The sun had just begun to rise near Virgin, Utah, when Hannah Bergemann began to climb. Shouldering her 35-pound downhill bike, Bergemann walked steadily up a narrow desert ridgeline. When she reached the top, she looked down the line that she and her dig crew had patiently carved out of the red desert sand, peeling back layers of prehistoric stone. If Bergemann felt any nerves, she didn’t show them. Then she began to ride. With precision, Bergemann followed the narrow track unwinding along the canyon wall as the landscape blurred beneath her wheels. She hit her first jump, flying over the gap. The ground dropped into wide-open air beneath her. Then came a series of ledges, a staircase made for giants formed out of rock layers, none of them laid straight. A steep chute sent her hurtling down until, at last, Bergemann arrived at a final jump. She soared over the gap cleanly, her bike’s suspension compressing under the force of the landing.