Adventurers of the Year 2008

When his guides asked why he was climbing Argentina's 22,834-foot Aconcagua, Francois Bon had an unusual response: silence. "I tried not to tell them," he says. After all, they might not have helped him reach the summit if they'd known he was planning to jump off.

Speed riding is the sport (if you can call it that) of rapid descent. Adherents leap from mountaintops and fly down sheer faces at near-free-fall speeds, guided only by a small, specialized paraglider. When the grade flattens, they touch down briefly to ski ridiculously fast before taking off again over the steeps. Bon, 36, is the grandfather of the sport. In 2006, he leapt off the Eiger and Mont Blanc. In 2007, he made some riotous runs in New Zealand's Southern Alps (shown above). But on March 31, 2008, he nailed his biggest prize yet.

"I never flew so fast before," he says. After an 11-day slog to Aconcagua's summit, the highest in the Western Hemisphere, Bon strapped on his chute and skis and rocketed down a near-vertical slope. He was almost instantly airborne. Thanks to thin, dry air, he came close to a hundred miles an hour, descending at a rate of nearly 31 feet a second. On the way, he dodged rocky spires, sailed over gaping chasms, and arced across virgin snowfields. By the time he skittered to a halt, he had plunged 9,000 feet in four minutes and 50 seconds. Bon's flight electrified the adventure world, and his video, which can be seen at acro-base.com, has received more than 16,000 hits. At press time, however, he was already on to his next challenge: Mount Everest.