BOB BURNQUIST is a professional skateboarder, but to let that be his definition is a little reductive.

The 32-year-old resident of Vista, California, is, by many tangible measures and especially by metaphysical ones, probably the best all-around skateboarder in the world, able to win X Games gold medals on the halfpipe or lay down eye-popping street segments for videos, as well as to consistently redefine what is considered possible in his sport. He might do this by riding completely around the inner circumference of a metal pipe (which includes skating upside down) or riding inside a pipe with a gap (which requires jumping upside down) or doing these tricks—or any of his tricks—switch (meaning backwards), or especially by doing the kinds of things he does on the infamous mega-ramp, a 360-foot-long, 75-foot-high plywood leviathan that has pushed skateboarding into terrifying new territory since appearing on the scene in 2003.

There are only three mega-ramps on earth. One is in storage and comes out for the X Games' "big-air" events, which Bob has won the past two years. Another is in Brazil, where Bob was born and lived until age 18. He built that one for a 2008 contest that he co-produced via his Encinitas, California–based production company, Zoobamboo Entertainment, and also won. It aired live on Brazil's TV Globo, to an audience of millions. The third mega-ramp is in Bob's backyard.

Bob didn't invent the mega-ramp; that honor goes to his pal Danny Way, a professional skater who jumped the Great Wall of China a few years back. The mega-ramp is a difficult contraption to envision until you've seen it in person, but imagine a wooden ski jump leading to the biggest kicker you can possibly conjure, one so tall and steep that your average professional skateboarder gets jittery just peering over its edge. The most basic jump goes something like this: You roll in from a platform about the height of a five-story building, reach 40 or 50 miles per hour on the 180-foot approach, then launch over a 50-foot gap—there's trapeze netting if you don't make it—land on a downslope, and zip toward a 30-foot-high quarterpipe that propels you another 15 to 25 feet into the air. You'll need to land back on the near-vertical face of that quarterpipe, and not on the deck up top or the flat bottom below, either of which spells almost certain injury.

You might recall this was the fate of Australian skater Jake Brown, who took a well-documented fall during the 2007 X Games. Jake wobbled slightly after landing a 720 (his first ever on the mega-ramp), which threw off his timing on the quarterpipe. Accidentally pushing himself away from the ramp as he went airborne, he fluttered and dropped 45 feet to the wood deck below, landing so hard that both of his shoes popped off. Bob, who was waiting his turn to go, thought his friend was "dead, paralyzed, in pieces. I was screaming, crying, freaking out," he says. Jake lay still for eight minutes, then suddenly, miraculously stood up and walked away (with a broken wrist, mild concussion, and bruised liver and lungs), and Bob thought, Oh, shit, I'm next. OK, Jake, this is for you. And he rode on down the ramp and won gold.

At this point, Bob can navigate the mega-ramp with ease, regular or switch. He can spin (many times), land just over the gap on a short platform known as a manual pad, perform a quick trick, then continue on toward the quarterpipe, where he might fly up and grind the soccer goalpost he sometimes places atop the deck, just for kicks. He can do a front flip over the gap, which no one else has even attempted.

Tony Hawk says he is "glad" the mega-ramp wasn't around when he was competing, and that it "has tested the human limits of riding a skateboard." Of Bob, Tony says, "Besides creating tricks previously thought impossible, he's taking existing moves and doing them at dangerous heights and over frightful distances." He's also unique, Tony says, because "his motivation is progression; not fame or fortune."

That's not to say, of course, that Bob won't compete. He shows up at competitions, mostly because his sponsors encourage it, and he tends to win: So far he's taken home 15 X Games medals (including six golds), was last year's World Cup of Skateboarding vert skater of the year, and was again the favorite in the big-air event at the 2009 X Games. But what actually drives Bob is something else: He's an athletic freak with a creative mind who's treating his sport more like a blend of math problem and art project. Bob Burnquist wakes up most every morning with one question on his mind: What else can I do?