THE YEARS AGO, GETTING TO THIS POINT would have been unthinkable. Sure, I'd reached summits before—riding lifts to the peaks of ski areas near my hometown of Denver in high school. But the first mountain I ever walked up was in the summer of 1994, after my freshman year at Pittsburgh's Carnegie Mellon University, when my best friend, Jon, and I climbed 14,255-foot Longs Peak, in Rocky Mountain National Park. If I had previously questioned my spiritual place in nature, here it was, perfectly clear and understandable when seen from that high mountaintop.

Even before I climbed Longs, I'd heard about people hiking all the fourteeners. Colorado has the highest concentration of 14,000-foot peaks of any state—54 according to the Colorado Mountain Club (CMC), though the exact number is open to debate. Beginning in the 1920s, the CMC has kept the list that most people go by, evaluating peaks since 1968 by the "300-Foot Rule," which states that, to be ranked as a fourteener in its own right, a summit generally must rise 300 vertical feet above the saddle connecting it with a higher mountain. But some climbers, me among them, prefer an exclusively topographical list of the U.S. Geological Survey's 59 named or ranked peaks above 14,000 feet.

However you count them, the mystique of the fourteeners is undeniable. At 14,433 feet, Mount Elbert is the highest peak in the Rockies; the east face of Longs, known as the Diamond, holds dozens of the hardest high-altitude climbing routes in North America. For millions of people a year, merely standing in the shadow of the Maroon Bells or Pikes Peak—whose views inspired the lyrics of America the Beautiful in 1893—is worth the pilgrimage. And for generations of hikers, the fourteeners inspire a more exalted sort of passion, the kind exhibited by the elderly gentleman who plopped down next to me on the summit of 14,150-foot Mount Sneffels, near Telluride, and explained between panting breaths that he'd drunk a beer on top of every fourteener. Sneffels was his last peak, and to celebrate, he pulled a five-liter keg of Warsteiner out of his pack. My descent was understandably wobbly.

My first climb was a farce. The wind turned my water and candy bars into useless bricks. Still, I was enraptured—I was soloing a fourteener in winter!

Since 1923, when young Denver businessmen Carl Blaurock and William Ervin climbed all 46 of the state's then-measured 14,000-foot peaks, the CMC estimates that nearly 1,200 people have summited all the fourteeners, even fewer than have scaled Mount Everest. Over the years, as better mapping and technology helped the USGS refine peak elevations, the number of recognized fourteeners grew—and the records piled up. In 1937, Breckenridge teacher Carl Melzer and his nine-year-old son, Bob, became the first to climb all 51 of the known fourteeners in a single season. By 1959, the USGS had recognized an additional mountain, and pioneering climber Cleve McCarty knocked off all 52 in 52 days—perhaps the most symmetrical feat of Colorado peak bagging. The current speed record stands at just over 10 days and 20 hours, set in 2000 by Oregon speed hiker Ted "Cave Dog" Keizer.

The summit chase is hardly confined to summer. In 1991, Carbondale, Colorado, writer Louis Dawson II—author of the definitive two-volume Dawson's Guide to Colorado's Fourteeners—became the only person to ski down every fourteener. It took him 14 years. This winter, two of my friends from Aspen, 33-year-old ski instructor Ted Mahon and two-time world extreme-skiing champion Chris Davenport, 35, are following in his tracks. Ted has 15 peaks left before he becomes the first to duplicate Dawson's feat. Chris is attempting to go one better: to ski the fourteeners in a single snow season.

I found myself drawn to the winter wilderness as well. Approximately 500,000 people set out on a trail to a fourteener each summer, according to the Colorado Fourteeners Initiative, a partnership of nonprofits dedicated to protecting these mountains. When I hiked 14,270-foot Grays and 14,267-foot Torreys peaks—two of the closest to Denver and Boulder—on a September weekend in 1997, it seemed like I passed half of those people on my way up and the other half on my way down.

At the time, I was just out of college, working in Chandler, Arizona, as a mechanical engineer for Intel, the computer-chip manufacturer. One night that fall, sitting on my bed combing through Dawson's Guide, I noticed something. "To date," Dawson wrote, "only one man, Tom Mereness of Boulder, Colorado, has climbed all 54 official fourteeners in winter." I pulled out my other guidebook, Gerry Roach's Colorado's Fourteeners. "Hard-core mountaineers climb all the fourteeners in winter," it pronounced. "This is a difficult goal for a single individual." Now I had an epiphany.

I'd harbored aspirations of being hardcore myself, and it appeared that Mereness (like Dawson) had climbed with various partners. Nobody, I realized, had climbed the fourteeners in winter alone. Since high school, I'd wanted to be the first person to do something exploratory. Here was my chance.

At this point I'd hiked seven of the fourteeners, and none of the difficult ones. It took a year of research and training, including a trial expedition up Arizona's highest mountain, 12,633-foot Humphreys Peak, before I felt ready to tackle my first winter fourteener—14,265-foot Quandary Peak, just south of Breckenridge—in December 1998. In retrospect, that kickoff climb was an utter farce, one that still slightly embarrasses me. I left my two-wheel-drive Honda CRX where it could no longer climb the snowpacked forest road and snowshoed up through the woods. Above tree line, the wind turned my uninsulated water bottles, candy bars, and peanut-butter-and-jelly burritos into useless bricks. Still, I was enraptured—I was soloing a fourteener in winter! Grinning naively, I struggled upward, bundling myself tighter in my ski jacket and pants, worn over manifold layers of cotton: turtleneck, hooded sweatshirt, and sweatpants. My breath fogged my goggles, then froze into shrouds of frost. When I tried wiping them clean, the Kevlar coating on my gloves etched the lenses as though I'd scoured them with sandpaper.

For two hours I trudged into the wind, nearly blind, without food or water, gasping for breath. Despite the hardships, or maybe because of them, I was euphoric when I finally reached the top. If the views from Longs Peak had set the hook, then Quandary's western vista of the Collegiate Peaks—the greatest concentration of fourteeners in the state—reeled me in. I fantasized that, at that moment, I was higher than any other person in North America. Even the carnivorous chill that snacked on my core through the sweat-laden layers couldn't strip the smile from my face. I was already discovering that I had a lot more inside me than I'd supposed.

Now I just needed to do something about all that cotton.