And frankly, the notion that my body might crap out halfway up the mountain—that I might succumb to altitude sickness or fall off some rocky precipice—didn't seem to cross Mim's mind. And pretty soon, it stopped crossing mine. I'd been vaccinated against hepatitis A, yellow fever, and tetanus. I'd tapped my local camping store for deep pink Duofold hiking tops, North Face fleece, "smart wool" socks, and khaki everything. (Why are outdoor enthusiasts so okay with this noncolor?) I'd rented a subzero sleeping bag. Then I'd stuffed it all into my pack, along with some energy bars, a roll of toilet paper, and a small bottle of Purell, and left for the other end of the earth.
The hike is under way. Tinqui vanishes behind us and Ausangate's snowy peaks emerge against a canvas of blue sky. When the late-day sunlight finally gives way to bracing winds—it's July, which is winter in Peru—I remember that my down jacket is packed away on one of our horses, alongside the thin tent I'll be sleeping in tonight. In what will become a nightly ritual, we all wriggle into every goose down item available and huddle around a table, eating quickly and desperately, our bodies reeling from the day's climb, our brains anticipating what's coming next. "You burn 3,000 to 4,000 calories a day in the mountains," Mim tells us.
By noon the next day, I believe it, as we plod toward a 15,580-foot pass, its moonlike landscape of coffee-colored earth dotted with the odd tuft of pale, prickly moss. Occasionally we see Peruvian women, squinting at us through lined skin. I wonder what they think of us, with our hiking poles, sunglasses, and maps showing that, after climbing and descending for miles and miles, we'll wind up back where we started.
They'd think we were nuts. Especially if they knew I could hop onto a horse anytime—but I won't.
As the days pass, I eventually watch others assume the saddle, yet somehow, despite my altitude-induced migraines and roiling nausea, I refuse to do the same. If anything, my symptoms harden my determination to push on, to return home with calluses, rock-hard calves, and war stories of being the first, the fastest, the strongest. Because what's the sense in traveling to a mountain on the other end of the earth to go for a trail ride?