The 22,834-foot Mount Aconcagua in Argentina one of the most accessible of the highest peaks in the Andes.
Day 13: Camp 2 (19,200 ft.)
At 3 am on January 17, under the light of a headlamp, I was suddenly feeling a new empathy for the aged. Between the altitude, the darkness, and my nearsightedness, I was having trouble getting organized. I had just finished a five-minute battle to get my boots on when Viesturs wandered over to check on me. "How you doing over here, Tim?" he asked, calmly surveying the chaos. "Let's think about getting those crampons on."

By dawn, nearly three hours later, we had crested the first long traverse and gained a ridgeline. The rising sun offered sweeping views of the Andes stretching out to the north, but the altitude and the cold were beginning to take their toll. I wriggled my chilled toes and balled up my fingers in my mittens, taking three breaths for every step. I was still cold and hypoxic. I managed to take a few photos; two were upside down.

I remember thinking how strange it was to be locked in a solitary battle with the mountain while constantly surrounded by people, either crammed three to a tent or staring at the backpack and boots of the climber in front of you. You rely on your guides and teammates, but the real struggle is the one in your head.

An hour later the sun had done little to warm us when we stopped again at 21,000 feet. The exposed ridge that lay beyond was being lashed by winds of more than 40 mph. I was tired and dazed, so Dave made me drink water and gnaw on a frozen Clif Bar. He was concerned. "If you want to keep going, I need you to take better care of yourself," he said. "Breathe more. Now."

We started on the exposed traverse but made it only a few hundred yards before Peter, who was in front, turned around. The wind was getting worse, and there were clouds moving in. It was 8 am, and we had been walking for four hours.

It started to snow soon after we got back to camp, and we spent most of the next day confined to our tents. But the bad weather turned out to be a blessing. If we had tried for the summit again the next day, I doubt I would have made it. I was completely spent, and it's no small task, after such a failure, to get excited to do it all over again. Still, with a day's rest I grew optimistic. We had gotten to within 1,500 feet of the summit. We had been close.