The Difference Is Luck : When a young idealist hikes alone into the Alaskan wilderness, an innocent mistake can prove fatal. : INTO THE WILD, By Jon Krakauer <i> (Villard Books: $22; 207 pp.)</i>

Any Alaskan can tell you about the disaster that got away--the squall that didn’t sink her kayak, the turbulence that didn’t swamp his bouncing Piper Cub, the camping trip that degenerated into a search for the trail back home. These stories usually end in one of two ways: “Boy, were we stupid,” or, more likely, “Boy, were we lucky.”

Chris McCandless was neither stupid nor lucky when, on April 28, 1992, he walked into the open country north of Mt. McKinley. He was young, though, a 24-year-old ascetic who thought that 10 pounds of rice, a .22 caliber Remington and a pack full of paperbacks would last him the summer. He had lived on less.

Four months later, hunters found McCandless’ emaciated body 15 miles from the road. His nearby journal read: “Too weak to walk out, have literally become trapped in the wild.” What McCandless hadn’t anticipated was the summer melt; the shallow river he had forded in April had turned into a frigid, roily tumult that blocked his return in July.

“Into the Wild” is Jon Krakauer’s compelling account of McCandless’ two-year odyssey from privileged honors student to ill-fated nomad. With a telling eye for detail, Krakauer has captured the sad saga of a stubborn, idealistic young man who gave away $24,000, abandoned his car in the Arizona desert and eventually even burned the cash in his wallet in his growing disdain for materialism.

Krakauer first covered McCandless and his fate for Outside magazine three years ago. That story garnered more mail than any other piece in Outside’s history. Many writers lauded McCandless for his courage and ideals; others--including many Alaskans--castigated Krakauer for “romanticizing” the ignorance that cost McCandless his life.

A slew of characters comes to Alaska every year to “live off the land,” a term that can mean anything from deserting your family to seeking communion with Henry David Thoreau. What sets McCandless’ story apart is his own tormented logic, his youthful foolishness and Krakauer’s success in bird-dogging the characters who met McCandless along the way. By painstakingly retracing McCandless’ steps from the vast Southwestern desert to the wheat fields of South Dakota, Krakauer tracks a young man whose opinions were becoming as hardened as his body. Over and over, drivers who pulled over to give the young hitchhiker a ride ended up feeding him, housing him, even offering him work. Almost everyone tried to give him money or clothes or advice.

In return, McCandless cited Leo Tolstoy, the Russian writer who had abandoned his own life of privilege, as the icon of a life of true renunciation. The margins of McCandless’ dog-eared paperbacks were filled with reflections on Tolstoy’s and Thoreau’s observations, and he repeatedly recommended them to others.

Ironically, as McCandless was cultivating surprisingly deep friendships with people on the road, his family had no idea where he was.

In May 1990, McCandless had graduated with honors from Emory University in Atlanta, bought his mother a Mother’s Day box of chocolates--a touching breach of his own self-imposed policy against giving or receiving gifts--and talked of a possible road trip. Walt and Billie McCandless never heard from their son again.

When August rolled around with no news, they went to Atlanta to find that McCandless had moved out of his apartment and disappeared. On returning home to Virginia, the couple were stunned to find all the letters they’d written over the summer; McCandless had apparently ordered the postal service to hold them for return after Aug. 1. A private investigator later determined that McCandless had donated the $24,000 left in his college fund to charity.

Krakauer’s ability to engage the McCandless family, and their obvious trust in him, are put to good use. We have not only a “before” picture to offset the “after,” we can also glimpse the blurring lines in between. There is an early story of how McCandless, as a sincere high school student, put up a homeless man in his unwitting parents’ Airstream, which was parked right in the driveway.

Krakauer makes no apologies for this sympathetic portrait and in fact weaves a personal narrative of his own troubled relationship with his father into the tale. In two distractingly detailed chapters recalling his own close call while mountain climbing solo in Alaska, Krakauer drives home the point that youthful hubris doesn’t necessarily mean a young man has a death wish.

Indeed, as Krakauer points out, there is a time-honored culture of the nomad in this country. It still calls to young men. Alaska is one of the last places big enough and wild enough to draw them--and big enough and wild enough to kill them. In the book, Krakauer also recounts the story of Everett Ruess, a young man who in the 1930s disappeared into the canyon lands of Arizona and New Mexico, where McCandless also spent time. The comparison is an imperfect one, though, because Ruess evinced none of the anger toward his family nor the disapproval of society that festered in McCandless.

As Tolstoy might say, each eccentric is eccentric in his own way. Although Krakauer rightfully reminds us of this odd fraternity, the very detail that makes McCandless’ story so riveting bogs down in the book’s digressions into other biographies. The engrossing, inexorable tragedy of Chris McCandless beckons.

For McCandless, the adversity and challenge were the thing itself. Lord knows, people tried to make his life easier along the way. But McCandless firmly stuck to his course, even as he maintained friendships with many who had given him rides and meals and jobs. One 80-year-old man, whose son had been killed in an auto accident years earlier, even wanted to adopt him.

These people are the true chroniclers of this American tragedy. Using their stories and McCandless’ own journals, Krakauer paints a picture of a young man who succeeded in living by his wits and the kindness of strangers for two years before heading for Alaska. Sometimes his fishing pole was his only source of food. When people tried to warn him that summer in the northern wilderness was a different proposition, he was not to be dissuaded. He had trained, he had read, he had dreamed for too long.

McCandless had been in Alaska three days when he finally strode into the tundra, making his way over the April snowpack in cheap leather hiking books and a fake fur parka. He had made no provision for a food drop or a pick-up plan--basic precautions for back-country travel.

No, McCandless wasn’t lucky that day he walked out into the country. He was foolish the way a 24-year-old ideologue can be foolish and tragically ignorant of the realities of northern survival. Yet he survived 112 days. Krakauer believes he would have lived to slip back out of the country if not for “one or two seemingly insignificant blunders”--an unforgiving oxymoron where bush survival is concerned.

Given Krakauer’s engrossing portrait, one can only wonder what life McCandless would be living today, had he made those 15 miles back to the road.