In a canyon in the Rocky Mountain Front above Fort Collins, Colorado, a young man named Jordan Temkin is flying his drone. He wears goggles that show him a video feed from a camera built into the drone, and he holds a console with twin joysticks that control the direction, angle, pitch, yaw, and speed of the flight. He sets the drone on the gravel at his feet. Just downhill is the Cache la Poudre River. The canyon rises to maybe three hundred feet above. He gives a command and the drone leaps to the top of the canyon in an instant. Then it is soaring over the highest places, looking down on Temkin, a small figure sitting on the tailgate of his car. At eighty miles an hour, the shadow of the drone flashes across the face of the rocks. Then Temkin swoops it down to the surface of the river, where it zips a few feet above the water. Because of where the sun is, the river is a blast of silver light. Temkin takes the drone upward again and veers into an intersecting canyon.