WHEN I FIRST MEET UP with McLean, in Salt Lake City, it's the winter of 2005 and the newspapers are full of backcountry carnage. MOUNTAIN MAYHEM, screams the front page of the Deseret Morning News. SEARCHES WREST ANOTHER BODY FROM MOUNTAIN, reads The Salt Lake Tribune.

"Four fatalities in two days," McLean tells me as I climb into his truck. "Things are spooky. We'll wait a couple days and let things set up. Then I'll show you a few chutes."

A year ago, McLean worked at the Forest Service's Utah Avalanche Center. It was a busy season for accidents, but 2005 has been worse. By early March 2005, Utah has recorded a total of seven avalanche fatalities, making this the deadliest season in 50 years—unnerving statistics, particularly considering the mushrooming popularity of the winter backcountry. Sales of off-piste ski gear have been brisk for gear companies in recent years; at Black Diamond, for example, revenues from alpine-touring equipment alone have grown about 20 percent annually since 1998. But lately, the backcountry has been biting back. I wonder aloud whether McLean feels any ambivalence about helping pioneer a sport that's so inherently dangerous.

"I'm more from the school of personal responsibility," he tellsme, arguing that the gear he designs is for experts who would be putting themselves in those situations anyway. "It's like if I were designing a Porsche. Should I worry that people might exceed the speed limit and crash?"

Two days later, at 4:45 a.m., I meet McLean and Polly Samuels at a parking lot across the valley from Alta Ski Area. This painfully early meeting time is standard procedure for McLean's dawn patrol. A handful of shadowy figures huddle around his Toyota pickup, discussing the plan. Above them, stars twinkle in a cold, black sky.

"Mark, you up for some touring after?" McLean asks.

"No, I gotta be in to work by nine," says Mark Santurbane, 29, a Black Diamond product-design engineer.

"Polly?"

She shakes her head. Judges don't consider chute poaching an acceptable excuse for courtroom tardiness.

Two more skiers arrive: Dylan Freed, a 19-year-old part-time college student, and Tom Diegel, 40, a freelance product designer. Doors slam, plastic boots knock against pavement. The faint outline of Mount Superior, the broad-shouldered 11,132-foot patriarch of the Cottonwood Canyons, looms above us.

Santurbane, Freed, Samuels, and Diegel head out, skinning effortlessly up the crusty remains of an avalanche set off a few days earlier by the Department of Transportation. The snow is firm, but we're packing avalanche beacons just in case. After about 400 yards, the slope angles upward to the point where we can no longer get traction with our skins. We strap our skis to our packs, and McLean hands me a ski pole with a Whippet grip before we start kicking our way upward again. "Take one of these in case you slip," he says.

The boot tracks disappear up a finger of snow known as Suicide Chute, which is so close to vertical that it looks like a church steeple frosted with snow. This is where I bid McLean adieu. I can survive your average black-diamond ski run, but this looks considerably more severe. I park myself at the bottom and watch, thinking back to a conversation I had with McLean about what, in his estimation, the theoretical limit of steep skiing is.

"Seventy-something degrees," he said, without hesitation. "That's in perfect conditions. In Alaska's Chugach Mountains. The snow blows in loaded with moisture, so it's sticky. Skiing an 80-degree slope might be possible, but you'll never find anything that steep in the Rockies. The snow's too dry to cling."

McLean would know. He once got pretty close to skiing that kind of slope, but he wasn't exactly descending on "snow."

For years McLean had kept his eye on a popular ice climb in Little Cottonwood Canyon called the Great White Icicle. The 650-foot gully was so steep it required ice axes, crampons, ropes, and belays to ascend it. In 1996, McLean and ski partner Mark Holbrook hauled skis almost to the top, then strapped on the boards and began slide-slipping their way down. "It was as much falling as skiing," McLean recalls. "I could make one or two turns, but you're building up speed as you come down, and the ice is so hard you can't edge. There's not enough friction for you to stop."

"When it's that steep," says the 42-year-old Holbrook, "it's not a pretty ski turn. You're leaning against a wall with your ice ax dug in. You slide a little, hop onto your other side edges, put your ax in, stop, breathe, and get ready for the next one."

From the bottom of Suicide Chute, I watch McLean ski down in the dawn light, at last observing the compact, efficient technique I've heard so much about. He makes a sequence of quick turns, his upper body steady and sure and facing down the hill, while his legs whip back and forth underneath him, making solid contact, controlling the speed.

"Andrew's incredibly gifted at making these controlled little hops and checks—it's as if his skis grow right out of his feet," says Louis Dawson, 53, a backcountry-skiing historian and the author of a guide to skiing Colorado's fourteeners. "For him, falling is very, very rare."

He doesn't fall, nor do any of the others. But I'm not fooled: They're making something terrifically hard look easy.

The Chuting Gallery categorizes descents like this based on a rating system developed in Europe: S, for skiing, followed by a number. An S0 is flat as a golf course. S5+ refers to a 55-degree slope—about the same pitch as some of the steepest roller coasters—where falling is "verboten." McLean's penultimate rating in The Chuting Gallery, S7+, is a 60-degree slope "with nasty obstacles. A quick and certain death if you fall."

Suicide Chute rates an S4: "40-degree slope with dangerous fall potential." The Great White Icicle rates an S7. The Chuting Gallery lists only one higher rating.

"S8," it says. "The future."