By Michael Lanza
At 5:30 in the morning in early April, the bone-chilling wind cascading off the Grand Canyon’s South Rim at 7,200 feet slices through my few thin layers of clothing. Four of us are following our headlamp beams in the dark down the South Kaibab Trail. We’re just minutes into a day that will also end by headlamp light late tonight—but only after we’ve hiked farther than any of us has ever ambulated in a single day.