NOTT AND MCNEILL spent the past 15 years working through a rigorous mountaineering apprenticeship. Sponsored by gear maker Mountain Hardwear, they climbed extraordinarily tough, technical routes that only other alpinists would know. McNeill, a Kiwi who'd relocated to Canmore, Alberta, made the first ascent of Dos Cuernos, on the Patagonian Ice Cap, in 2004, put up three new hard lines in Greenland, and climbed extensively in Canada and Alaska. She chose to do most of her expeditions with other women. Nott grew up in Vail, Colorado, and was a serious backcountry skier before a friend introduced her to ice climbing in 1990. She completed the first ascent of Glass Onion, a difficult ice-and-rock route in southeast Alaska, made four attempts on Patagonia's Fitz Roy, and climbed extensively in the French Alps.

"Climbing gives me so much joy, so much happiness," Nott told me when I interviewed her in the fall of 2003; she

"Sue's motivation never wavers," said Nott's boyfriend. "When it gets grim, it's hard to find one reason to go up. Sue always finds that one."

had been selected by this magazine as one of the top female athletes in the world. At the time, she was living in Chamonix, France. That year, climbing with her boyfriend, John Varco, Nott had become the first American woman to complete a winter ascent of the north face of the Eiger. "The climb was great," she told me enthusiastically. "It was cold and classic and everything you could possibly hope for."

When I spoke with Varco that fall, he gave her the ultimate alpinist's accolade: "Sue's motivation never wavers. She wants to get to the top. When it gets grim, there are a thousand reasons to go down, and it's hard to find just one reason to go up. Sue always finds that one."

McNeill was equally committed to the climbing life. After moving to North America in 1994, she spent four years as an instructor at Chicks with Picks, an all-women ice-climbing school in Ridgway, Colorado. According to cofounder Kim Reynolds, a close friend of both women, McNeill had three rules: "First, you could never say you're sorry while climbing," recalls Reynolds. "Second, as Karen lowered you off a climb, she would stop and hold you one foot off the ground until you said, 'I am a goddess.' Third, after you got off the climb, you always had to state one thing you did well."

For the past three years, McNeill worked as a teacher at the Morley Indian Reserve, near Canmore. "She encouraged the kids to get rid of the clutter and pressure of society, tune in to themselves, and pursue their own dreams," says Margo Talbot, 42, a Vancouver-based guide for Antarctic Logistics and Expeditions and a good friend. "She didn't have many female role models, so she lived her own dreams and grew into the role model she wished she'd had."

In 1999, Nott and McNeill teamed up for the first time, climbing in Peru. It was a natural fit: two women who were instinctively drawn to the mountains and found through climbing the confidence and courage to break out of hackneyed female stereotypes. In 2000, they climbed the west ridge of 21,466-foot Shivling, in India's Garhwal Himalayas, in a grueling five-day push. In 2004, they paired up to climb McKinley's highly coveted Cassin Ridge. They set out with five days of food and seven days of fuel. On the tenth day, when they didn't show up at camp at 14,200 feet on the West Buttress, the standard descent route, the Park Service launched a search-and-rescue mission. A high-altitude Lama helicopter found them snug, if hungry, in their tent on the summit, having become the first female team to complete the route.

Mount Foraker was their most ambitious climb to date. One of the most difficult and dangerous mountains in the Alaska Range, Foraker is described in one guidebook as the "ultimate test-piece and one of the world's finest alpine challenges." Since 1979, only 24 percent of climbers who've attempted Foraker have summited, and 19 have died. Of the 26 climbers on the peak this spring before McNeill and Nott began the Infinite Spur, not a single one summited.

The route up the Infinite Spur has been even more unforgiving. When renowned mountaineers Michael Kennedy and George Lowe put up the first ascent of the route, in 1977, it took them eight days and more than 80 pitches of roped climbing. Both men survived bad falls. The route was not repeated until 1989, then not again until 2000. All attempts on the Infinite Spur between 2002 and 2005 failed.

No one I spoke with described the two women as reckless or fearless or puffed up with their own egos. They were driven and competitive but realistic. They went into a climb with a plan and knew when to call it off. They'd turned around on 19,127-foot Taulliraju, in Peru, because they were dehydrated; high winds, deep snow, and ice-plastered rocks had forced them to abort their attempt on Shivling's east ridge. They retreated and, a week later, summited via the west ridge.

Both of them understood that for alpinists, death is just a mistake away. "Mountains make me dig deep, pull into myself, and overcome," Nott told me in 2003. "Alpine climbing is extremely hard mentally. You can't have meltdowns, because you can't, to survive. You get used to being careful and making deals with the devil: Just get me past this serac, just get me through this bergschrund, just get me through this storm . . ."