Dean S. Potter, Sky Flier

See the next 2009 Adventurer of the Year >>

Video: Watch video of Dean Potter's incredible feats >>

On a sunny afternoon in mid-August, Dean Potter stepped onto a tongue of rock just below the summit of Switzerland’s Eiger and jumped off. At first he plunged toward a ledge 600 feet below, then air gathered in his wingsuit, his forward trajectory kicked in, and he began to fly.

Speeding three feet ahead for every one he dropped, Potter, 37, watched as ice slopes gave way to talus, then to fields, then cabins, then houses, restaurants, and eventually a town, which he veered away from to avoid the power lines. By the time he pulled his chute and drifted to Earth, Potter had spent two minutes and 50 seconds in flight. It was the longest BASE jump ever, covering some 9,000 vertical feet and nearly four miles.

In the rarefied world of BASE jumping, this was big news, but to Potter it was just another step in an ongoing transition. He is one of the best known rock climbers on the planet, renowned for daring free solos (no rope, no harness) up some of the world’s tallest rock faces. But this year, Potter made headlines with hardly any climbs at all. Instead he free soloed a hundred-foot slackline over the yawning abyss at Yosemite’s Taft Point. He pushed his new sports of BASE lining and free BASE (slacklining and climbing, respectively, while wearing only a parachute as protection from a fall). In short, this was the year that Dean Potter outgrew the title of climber and became something other, something that defies definition—awe-inspiring, maybe crazy, and most definitely badass.

Originally published in the December 2009/January 2010 edition of National Geographic Adventure