SAFELY NAVIGATING THE VERTICAL minefields of alpinism requires years of experience, and one obvious question is whether Haley will push it too hard, too soon. But so far, he's proven himself on the highest stages. Last January, in a typically ambitious effort, Haley and an Argentine climber named Rolando Garibotti, 37, took on a project that alpinists have been fantasizing about and failing at for 20 years: the Torre Traverse.

Cerro Torre is one of the most iconic mountains in Patagonia, a 4,600-foot spire that rises like an index finger above three others, Torre Egger, Punta Herron, and Cerro Standhardt. Together, they make up a stunning, serrated fin of granite with a legendary reputation for thrashing expeditions. Torre Egger is considered the hardest summit to reach in the Western Hemisphere, and Cerro Torre is probably a close second. Climbing any of them is an incredible achievement for the best alpinists. Traversing all four in a single attempt—7,200 total feet of climbing in some of the world's most unpredictable and unrelenting weather—borders on the absurd.

On January 21, Haley and Garibotti began racing up Cerro Standhardt into a blizzard, anticipating a rare break in the icy winds that rake the peaks throughout the austral summer. To guess wrong and get caught on the ridge in a storm would force a frightening retreat—hours of tedious rappels, each with progressively less protection, in vertical gullies bombarded by falling ice.

"They were out on the edge there," says alpinist Mark Westman, 38, one of Haley's regular partners. "If they hadn't reached the summit, they were looking at quite an epic to get out." At the end of the third day, the pair came to the hardest pitch of the traverse, a 160-foot-tall tower of crumbly rime that serves as the final, formidable obstacle to the top of Cerro Torre. Since this ice was too loose to hold screws or other protection, falling would likely be catastrophic.

It was Haley's turn to lead. Belayed by Garibotti, he spent four hours carving out a chimney with an ice ax, inching higher and bracing himself in the snow tube until he popped out into the sunshine, soaking wet. Soon he was standing on the 10,262-foot summit.

How notable was this climb? Jim Donini, the 65-year-old president of the American Alpine Club and a member of the first team to climb Torre Egger, in 1976, called it "the most significant achievement of the year in the Western Hemisphere." But it was just one of half a dozen major climbs Haley had pulled off in a furious blitz that started when he was 21. These included an earlier climb of Cerro Torre with 38-year-old Kelly Cordes; a first winter ascent of Alaska's storied Mount Huntington with 23-year-old Jed Brown; and a stunning new route on British Columbia's Mount Robson with America's top alpinist, 36-year-old Steve House.

Haley always climbs alpine style, which means he goes for the summit in a lightning push with the absolute minimum gear. Climbing this way requires years of hard apprenticeship in the mountains, but most of Haley's partners say he's already as advanced as many of the best. "I've never seen anyone attain this level of proficiency and success at his age," Donini says. "I think it's unprecedented in American climbing. In fact, I know it is. I don't throw praise around. I make an exception for Colin."