When the Winter X Games hit Aspen in January, the world's snowboarding greats were all present, throwing double corks over the halfpipe. But one was notably absent: Jeremy JonesThe world's preeminent free­rider was busy prepping for his upcoming expedition to the glaciers of Alaska, where he'll strap a tent to his back and camp out between blizzards, waiting for the weather to ease so he can locate, climb, and then snowboard down chutes and couloirs so hairy that he is one of the few humans alive who would attempt them.

For the past three years, the eight-time Big Mountain Rider of the Year has dedicated himself to hiking and climbing up mountains so that he can snowboard down them. His primary tool for this is a splitboard, a snowboard that breaks in two to become skis. Jones' enthusiasm for the splitboard has popularized the genre, and in 2009 he founded a company that manufactures them. His ultimate goal is to get young boarders to follow him out of bounds.

Jones' transition to a purer, more old-school brand of adventure is not that surprising given his background. Now 36, he learned to snowboard before parks and pipes were ubiquitous. "I would have loved them, but growing up, the parks just weren't there," says Jones. "So to me, it's always been about riding the whole mountain, finding the stashes and the top-to-bottom line that connects them all." From his onscreen introduction in the 1997 film 'Totally Board 6' – he dropped into a nearly vertical Alaskan face, triggered, and then disappeared into an avalanche, only to reappear from the tidal wave of white at the last minute and ride to safety – the Vermont-raised resident of Lake Tahoe has spent the better part of two decades seeking out and riding some of the most difficult lines on Earth. As Travis Rice, the world's best all-around snowboarder, once said, "Jeremy is breaking down the boundaries of 'I can't.' "

What makes Jones all the more unusual is that, in person, he's short, skinny, and quiet, with an almost Zen-like presence, lacking the bravado you'd expect from a pro snowboarder. The morning I meet him to go backcountry boarding, it is in the parking lot of the Truckee Community Recreation Center, where he's just dropped off Cass, his three-year-old son, at preschool, after getting his daughter, Mia, six, onto her school bus – a dad's daily duty. "If I miss that," he says, "it's a major bummer. I have to drive her to King's Beach" (a 15-minute drive). That, it seems, is every bit as daunting to Jones as the prospect of ice climbing his way to an Alaskan spine.

Though raised in a family of skiers, Jones picked up a snowboard at age nine and has taken a methodical approach to the sport ever since. He keeps a camera with him at all times and snaps photos of rugged peaks and ranges, seeks out ribbons of snow in places where no one else would look, and then catalogs these first descents on a mental "hit list" that he systematically works through.

Jones has roamed the planet with the perspective that any mountain is a potential run. For much of his career, he reached peaks by chopper, like other free­riders of means. But for the past three years, he has been powered by his two feet. The splitboard, especially, has been a breakthrough, leveling the playing field in the backcountry between skiers, who've been alpine-touring for years, and snowboarders, who've historically had to unbuckle, strap a board to their back, and post-hole through deep snow to reach the powder far from lifts and trails. And Jones has been its most passionate proselytizer. As Pat Bridges, the longtime editor of 'Snowboarder Magazine,' puts it, "The resurgence of the snowboard as a vehicle for exploration beyond resort boundaries can directly be attributed to Jeremy." Danny Davis, one of the best halfpipe riders on Earth, says simply: "Jeremy built a whole new category of snowboarding."

Exploration is the philosophy behind a trilogy of films Jones is producing in conjunction with Teton Gravity Research, the ski-porn company owned in part by his two older brothers. 'Deeper' was the first: It debuted in 2010 and is as much about the climbs up as the rides down. The climbing shown onscreen has resonated with snowboarders, not only because it shows the additional effort involved but because there's a democratic motive, too. "Taking a helicopter to go snowboarding is attainable for maybe one percent out there," says Jones. "There are 30 movies coming out, and all the big-mountain riding in them starts from helicopter. [The ski-film industry] is sending the message that if you want to do world-class free­riding, it needs to be done from a helicopter. We're showing a different way."

When I meet Jones in mid-December, the peaks that ring Lake Tahoe are devoid of their typical white winter cover, but Jones, as adept in the backcountry as a mountain goat, knows of at least one last stash of snow. It might be crusty and windblown, tucked among trees and rocks, but Jones is determined to take me to it. It's just going to involve serious effort to get there.

The nearly snow-free landscape seems an apt foreshadowing of a future Jones is trying to help prevent: In 2007, after traveling to some of the coldest places on Earth and watching glaciers recede firsthand, Jones decided to become an activist. He founded Protect Our Winters, a group that mobilizes the winter-sports community against climate change. In the time since, POW has pushed resorts and manufacturers to get greener, provided education for children, and lobbied in Washington against coal-fired power-plant projects.

Jones' revelation was also a major impetus in his conversion to foot-powered backcountry snowboarding. After spending so much of his career flying by helicopter in order to ride more and more difficult lines, the process started to irritate his growing environmental activism – and give diminishing returns. "I felt like I had taken my snowboarding as close to the edge as I wanted to," he says. "I'd gone as steep as I could. I'd ridden over as big of cliffs as I wanted. I'd gone as fast as I wanted."

For our half-day trek into the backcountry, Jones outfits me with a prototype splitboard from his line, which has been sold out and back-ordered since the day it launched in 2009. It's early on a clear, crisp Friday when we meet up with Ryland Bell, a Jones team rider, at a trailhead behind Alpine Meadows resort. We put "skins" (adhesive strips that give skis grip for uphills) on the two halves of the board, assemble our collapsible poles, and stuff sundries into our packs. Then we trudge across a clearing in our snowboard boots, past an idle lift, and into the woods.

Two hours and 1,800 vertical feet later, I unbuckle my boots, scramble over some rocks, and collapse onto the craggy top of Grouse Ridge, a 7,000-foot-plus mountain with 360-degree views of Lake Tahoe – and beyond it, thousands of acres of backcountry rarely accessed by anyone. Jones points out a ridge with a band of cliffs that would be snow-covered in a more typical December and identifies it as terrain featured prominently in 'Deeper.' "I've looked at that view 1,000 times. But one day I just saw it and thought, 'Why aren't we riding that?' " The answer, unstated, is because the area is off-limits to snowmobiles and helicopters, and to reach it requires hiking or skinning another half-day and camping overnight. "That's 'Deeper' in a nutshell," he says.

Maybe the happiest by-product of giving himself over to human-powered ascents is that reaching high peaks under his own power is "a much fuller experience, to find this dream line and figure out how to do it on foot – the high from that is way higher," he says, than the one he was getting on heli-trips, in which he'd knock off four or five major descents before lunch. "At the end of the day, that's what it's about – what gets your rocks off the most." It has also changed the way Jones boards at home. "Even in Tahoe," he says, "it seems like 80 percent of the time, I'm riding something I've never ridden before."

Jones hopes that more young snowboarders will follow his lead. "There's a customer who's not being served, and there are a lot of 25-, 30-, 35-year-old snowboarders who have been banished from the sport because they're not 15 and trying to learn a new trick." The industry, he thinks, is doing itself no favors focusing on youth. "Snowboarding has put so much energy into trying to emulate skateboarding. The problem with that is you get this attitude where, if you're not in the park trying to learn a new trick, it's time to move on. And a lot of people do."

Rider Danny Davis has made his career in the halfpipe but sees the power in Jones's message. Jeremy, he says, "brings snowboarding for life to the table. I won't be flipping in a halfpipe forever, but he will be riding new lines until he dies." It strikes me that Jeremy's goal with Jones Snowboards, and with the trickle-down effect of his movies, is to help snowboarding accept its middle age – no offense to the guys in the pipe.

Which isn't to say he doesn't still love flying downhill. Up on Grouse, he points to the two slabs of my board to indicate that I should begin assembling it, then peels the skins off his. He walks to an opening in the rocks where the icy snow has softened, offering up a mini-bowl that leads into some trees. He sits down to clip in. "I want you to take it real mellow," he says, "like second gear. Just enjoy the ride." With that, he drops straight into the narrow chute, cuts a hard left, and disappears into a huge, arcing turn that sprays wet snow into the bright, blue afternoon.