Nature–How beautiful it looks on the cover of the Patagonia catalog; how profound it is in the hands of the right travel writer. If nature didn’t exist, we’d have to invent it, because otherwise there’d be nowhere to go in the summer but Atlantic City. Nature teaches us about death, which is an abstraction to most of us now, something to be warded off with the right balance of lipoproteins. In nature we learn the limits of our endurance–three minutes without oxygen (even less if we spit out our scuba mouthpiece underwater to shout Ohmigod, Harry, it’s a shark!), three days without a shower, a week without a newspaper. Nature is filled with gravity, which makes the white-water rivers run and propels skiers down mountains, and teaches us, as one unfortunate man in Colorado discovered just a couple of weeks ago, that a 260-foot bungee cord is of no use at all if you’re jumping from 190 feet up. Nature has wild animals in it, which make for every American’s worst nightmare: being eaten alive and discovering there’s no one to sue.

Yet we come anyway, jouncing eight at a time down the class V rapids of the fabled Bio-bio, hurling ourselves down black-diamond ski slopes with the pitch of a mansard roof, immersing our precious hides in the Pacific Ocean hoping to see a shark before it sees us. “Adventure travel,” a loose designation more or less coterminous with “gentlemen not expected to shave,” has grown in 20 years from a statistical footnote to an $8 billion business, perhaps as much as a fifth of the U.S. leisure-travel market. Nature stands at the intersection of practically every fashionable trend in American society-fitness, environmentalism, multiculturalism, Western wear and, of course, affluence. Deluded by the readouts on their stationary bicycles (Holy cow, 28,650 kilogram-meters!), people want to show what they can do against the Matterhorn; sales of mountain bikes went from 500,000 a decade ago to almost 7 million last year. Or they pit themselves against the mighty Colorado; more than 22,000 people a year float through the Grand Canyon, 100 times as many as in 1960. To put this into perspective, on average more than 22,000 people a day visit Disneyland.

Adventure travel has the snob appeal of all serious pastimes. You have to really want to see the red-rock desert of southern Utah to traverse it on a mountain bike, a mode of transportation that combines the strenuousness of continuous push-ups with the comfort of failing down a flight of steps in a shopping cart. The Middle Fork of the Salmon River in Idaho winds 100 miles through cool forests of ponderosa pine and desert canyons of rock and sagebrush, rumbling over boulders the size of Volkswagens, but it takes six days to do it; you could cruise the whole Caribbean in that time. People who join the Cambridge, Mass.-based Overseas Adventure Travel for a monthlong trek up the 20,000-foot Island Peak in Nepal, including a stop at the famous Tengboche monastery “where countless Everest expeditions have received the blessings of the reincarnate Rinpoche,” probably aren’t the same ones who drive their RVs to Graceland.

Yet adventure travel also appeals to idiots. Bungee jumping, which when introduced to the West in 1979 looked like a fad with all the staying power of streaking, is still popular; in fact the two have come together in the form of naked bungee jumping, so popular a pastime that the AJ Hackett Bungy company had to rescind a standing offer to let people jump free in the nude. Bungee jumping requires nothing but mass, as Hackett proved when they jumped a man weighing 450 pounds. Between these extremes the adventure-travel field has proliferated into all kinds of specialized niches: trips for cancer survivors, executive-bonding trips intended to forge a world-conquering management team and climbs for women only, in which nobody is made to feel bad if she looks up at the mountain and decides to spend the day reading instead.

Nature can be a cruel master. But a cooler full of beer can help cushion its rigors. The industry is driven by the growing demand of people in their 40s for “soft adventure,” harking back to their first camping experience, in their own backyards. The generation that once hitchhiked across Europe with nothing but a McGovern button in its pockets now wouldn’t think of setting off into the wilderness with only one kind of wine. “Frankly, it’s amazing to us to see baby boomers seeking creature comforts,” says Judi Wineland, founder of Overseas Adventure Travel. But she has no choice but to cater to it, bringing hot showers, beds and night tables into the Serengeti.

One can join a backpacking trip with the Sierra Club and experience nature in all its blistering imminence. More often, though, Americans put themselves in vehicles of some kind and turn the decisions over to commercial guides-those preternaturally sinewy and cheerful young men and women, often taking 12 years or so off from graduate school, who combine intimate knowledge of the local culture and natural history with the cooking skills of Julia Child and the soothing competence of an airline pilot. Typically the guides make camp (including dining tables and chairs), do all the cooking and cleaning up. and-depending on the outfitter-may or may not erect the clients’ tents for them. The Middle Fork River Co., based in Sun Valley, Idaho, takes its obligations to its guests’ comfort so seriously that it has recruited a sommelier to be trained as a river guide: supplies for a six-day rafting trip by 24 people include 144 freshly ironed linen napkins.

Well, and they deserve it, as well as the Cabernet Sauvignon with the rack of lamb and the chenin blanc with the poached salmon. After all, they spent the day on the river, or in some cases in the river, thrashing around in roiling After only a day away from being snow. That sense of entitlement, of luxuries hard won by exertion and discomfort, is one of nature’s most subtle attractions. The experience of running a class IV (“Difficult”) rapids, after all, is phenomenologically indistinguishable from an amusement-park flume ride: you slide helplessly along your watery chute like a peach pit flushed down the toilet, you get drenched and ruin your camera. Even the screams sound the same. Yet the two experiences are in no way comparable. The amusement-park ride demands of you only the minimal intellect not to stand up in the middle of it. It is sheer sensation devoid of context; do it once and you’ve exhausted its potential. Whereas each moment on the river is unique, the unpredictable product of rainfall and snowmelt, the jamming and unjamming of logs along its tortuous course.

“I’ve been down the Middle Fork of the Salmon a hundred times, and it’s never the same twice,” says Greg (G.T.) Thomas, a Middle Fork River Co. guide. You paddle like hell, but your fate is in your guide’s hands, and sometimes he or she drops it. Victor Camacho, a Connecticut anesthesiologist, discovered this when his raft flipped over in Lava Falls on the Colorado. “I thought I was going to die,” he says. “I saw bright lights and thought I was entering the afterlife.” Actually, he was seeing daylight as his life jacket shot him toward the surface, but it was enough to make him swear off white-water rafting for the rest of the afternoon. Yet there he was on his next vacation, shark-diving near San Clemente Island. Why does he do it? “Going down with the sharks.” he says, “gives me the same feeling I had the first time I put someone to sleep. It helps me not take my work for granted. My work and shark diving are both life and death.”

Of course, Camacho did his shark diving inside a submersible cage, so he had a somewhat greater tolerance for error there than in the operating room. The danger in adventure travel is often more apparent than real. “It’s been years since an elephant trampled a safari vehicle,” says Scott Senauke, marketing director of Wilderness Travel, in Berkeley, Calif., yet the knowledge that it could happen imparts a latent thrill to the experience of watching these frequently somnolent beasts. Adventure travel teaches you that there are two kinds of danger in the world. One kind you undertake with full knowledge and awareness, and it invigorates your senses and leaves you exhilarated. “When I’m in serious white water, I’m focused, I’m going all out, my feeling is ‘OK, here’s what I have to do, now go and do it’.” says Anne Bardsley, 28, a biologist from Boulder, Colo. (“And I’m saying, ‘Ohmigod, I’m in a cataract, I hope to God I make it out alive’,” adds her traveling companion Scott Knauer.) The other kind of danger you blunder into by your own stupidity, and it makes you feel like a schmuck, especially if somebody else on the trip was watching. Mountain-biking through Canyonlands National Park in Utah, losing the trail and beading down a dry wash leading directly to a 300-foot drop is an example of the second kind. The fact that the wash looked almost exactly like the trail would constitute a perfectly good excuse in most arenas of civilized life. But it wouldn’t make a bit of difference on the way down.

As it happens. This is just the attitude many corporations want to foster in their employees: screw up and you’re dead meat. Or, to put it more positively with rigorous and disciplined training, seemingly impossible goals are achievable." That is the message of Extreme Connection, a Utah outfit that supplies free-climbers, solo trekkers and extreme skiers to speak at corporate functions, providing the motivational wisdom that until recently has been presumed to reside exclusively with college basketball coaches. Some companies go further and actually send their employees out into the wilderness. Sun Microsystems may or may not make the world’s best computers, but how many other companies can claim that their executives have scaled Mount Tongariro in New Zealand? The value is in learning to work together so that the whole group gets to the top, according to senior training specialist Bob Daubenmire. “They will go at the slowest pace of the slowest member to make sure they take care of everybody as well as meet their goal”-an ethic that has never been prominent in American business.

Most such programs are modeled in some degree after Outward Bound, the nonprofit wilderness school whose motto–“To serve to strive and not to yield”–has inspired executives of enterprises as diverse as American Express, Procter & Gamble and Sara Lee, who may or may not rather have been playing golf. The brochure for Outward Bound’s “Professional Development Programs” is a highpowered testament to the bottom-line benefits of tying executives together with rope and having them pull themselves up a mountain. “Our mission,” says Barry Rosen, Outward Bound vice president for marketing, “is to see that [wilderness skills] become the vehicles for increased self-esteem, selfreliance, concern for others and care for the environment.” The programs are notoriously rigorous. “They push you to your limits,” says Ken Washburn, a Providence, R.I., industrialist who took his 16-year-old daughter on a “fatherteen” trip a few years ago. “If they think you can climb a 2,000-foot hill they’ll find one 4,000 feet for you.”

Washburn, though, doesn’t think much of wilderness bonding as a management tool. “I run a company,” he says, “and our people are our most important resource, but they don’t have to walk 25 miles on a cup of water and catch their own food to do their jobs.” For that matter, there are those who believe that it is a desecration of nature to use it, even indirectly, as a venue to teach managers how to sell more shampoo. In the hands of men, says Alaska’s Rachel Holzwarth, “the wilderness becomes another corporate ladder…it’s the military model, trying to make men from wimps.” Holzwarth helped found Alaska Women of the Wilderness, which rejects the whole goal-oriented approach to nature, reflected in phrases like “conquering the mountain” or “hitting the trail.” Her preferred term for those activities is “being with Mother Earth.” On a rope-assisted climb at Matanuska Glacier, 100 miles northeast of Anchorage, Alaska, she lets the group vote its choice of route, and when it chooses an easy one, and two women decide they don’t want to try that one either, nobody tries to convince them that they’ll let down the company if they stay behind.

Lucky thing none of them is married to…oh, Steve Elliot, of Toronto, a 42-year-old managing partner in an accounting firm, who recently returned from a climb of the 12,139-foot Gunnbjorn, the highest peak in Greenland. He’d already scaled the highest peak in Antarctica and rafted down class V rapids in Turkey, Zambia and Uzbekistan. Women can do this stuff, too, of course, but Elliot’s former wife sometimes just wanted “to go to St. John and lie on the beach.” You call that a vacation?

Of course, Elliot’s feats are kid stuff next to Skip Horner’s, his guide on the Gunnbjorn climb, who has led trips up mountains in central and East Africa and down rivers in Albania. Horner became a guide for the challenge of getting someone who spends his day writing software up and down a mountain safely. “I knew I could climb Everest,” he says modestly “but I didn’t know if I could get an amateur up there with me.” Turns out he could.

And yet, how does Horner stack up next to Bob Jacobs, who used to guide trips up Mount McKinley but moved away because he couldn’t stand the crowds? (Around 1,000 people a Year climb North America’s highest peak.) Now Jacobs runs a guide service that specializes in taking people up mountains no one has ever climbed before. He figures there are enough such peaks in Alaska to last another 15 years. Then he’s not sure what he’ll do.

Maybe he can try bicycling up them.

Most raft trips are fine even for beginners. Don’t try these without an experienced guide. And don’t bring anything that can’t get wet.

5-6 days, $950-$1,500

105-mile trip features crystal-clear water, 80-class III-IV (medium-difficult) rapids.

5-15 days, $1,100+

240-mile waterborne geology lesson offers great side hikes, good trout fishing

9-12 days, $2,000+

Ride through 180 miles of untouched wilderness past hanging glaciers and icebergs.

5-10 days, $2,000+

Hard-core Andean river serves up loads of class V (very difficult) white water. Not for the fainthearted.

SOURCE: AMERICA OUTDOORS

If you’re in decent shape, you can head for the hills with a good pair of boots, a guide and a few mountaineering lessons.

4 days, $370-$630

rocky 13,776-ft peak offers routes from simple hikes to advanced rock climbs. Cost includes 2 days of instruction.

3 days, $335

Snow and glacier climb to 14,410 ft. Includes 1 day of mountain-safety training.

2-5 days, $185-$550

Courses teach beginners ice-climbing techniques and, notably, how to handle cold-related perils.

5-7 days, $350-$1,500

Technically just a long hike, but thin air at 19,340-ft summit a lung-buster.

SOURCE: AMERICAN ALPINE CLUB, OUTFITTERS

Get maps and go at your own pace, or sign up with an outfitter and let a van carry your stuff. Some popular routes:

Astoria, Ore., to Yorktown, Va.

4,500-mile ride is the mother of all bike tours. Strong riders do it in two months.

Grand Junction, Colo., to Moaab, Utah

Superb 140-mile off-road trail through canyon country. Strenuous but doable.

Crescent City to San Diego

Stunning 990-mile coastal route can be dangerous. Narrow, winding roads demand caution.

SOURCE:BIKECENTENNIAL