For 13 summers, Timothy Treadwell pitched his tent in Alaska's grizzliest bear habitat. Whether he was operating on a courage surplus or a sanity deficit depends on whom you talk to, but consider that during these seasonal forays into bear turf he carried no rifle, no mace and no electric fence.

He also had no scientific credentials or institutional backing, so his seasonal presence was something of a puzzler to many. Until he got famous.

Though he summered in ground zero of bear country, Treadwell didn't obey its most widely accepted edicts. He camped too close to bear trails, too near their salmon spots. He was known to leave food inside his tent.

But that's not the half of it: Treadwell approached mothers with cubs and even pet a few bears. Repeat: He would pet wild grizzly bears. If that's merely stupid, there's also the completely inexplicable. As Nick Jans reports in his wildly interesting book The Grizzly Maze, Treadwell was often seen crawling around on his haunches in an effort, presumably, to become more bear than man. He was even spied tromping around a tidal field of bears in a tuxedo.

For his efforts, he was awarded more publicity (by People, Letterman, the Discovery Channel) than any wildlife maven in recent memory. Treadwell took a "grizzly bears have been misunderstood" tact, and, if not in so many words, promoted a touchy-feely image of the creatures, whom he bestowed with names Disney would surely reject for being too cute: "Mr. Chocolate," "Booble," and "Cupcake" are but a few.

As his fame grew, so too did his financial backing from environmental glitterati like Leonardo DiCaprio. But Treadwell also drew a healthy number of critics, especially in Alaska, which knows little love for nature-boy dilettantes.

On Oct. 5, 2003, Treadwell got what many feared, and some expected: an inevitable comeuppance. A day before he and his partner, Amie Huguenard, of Boulder, were to be picked up by bush plane, they were attacked and eaten. Arriving the next day, park rangers filled two body bags with 40 pounds of remains.

Jans does a wonderful job sifting through the Treadwell of self-made myth and the more contradictory human being. He applies a healthy dose of skepticism to his subject, but without bludgeoning him with judgment.

Of course, Treadwell's preferred personal history is familiar enough, though it's the sort of narrative we're more used to hearing on Christian television: This time, salvation from a life of sin (drugs, alcohol, fighting) came not from the Creator, but from furry brown mammals. Bears offered a reason to live, and Treadwell returned the favor by giving his life to protecting them.

As Jans notes, this narrative conveniently omits Treadwell's middle-class upbringing, his thwarted career as a competitive diver and the influence of his family and girlfriends. Treadwell was actually born Timothy Dexter in Long Island, but like so many before him, he moved West to fashion an identity better suited to his ambition.

Treadwell's friends may have had deep reservations about his tactics, but, according to Jans, no one ever doubted his devotion to the animals. This was in evidence during the off-season, a.k.a. hibernation, when he tramped around the country sharing his photos and talking about bears to school kids, often for free.

The reason Treadwell insisted it was necessary to spend so much time with the bears was his insistence that his presence was a bulwark against poachers. Otherwise, he claimed, the 800-pound beasts, which were hardly struggling without him, would be gutted for their gall bladders. (These fetch a tidy sum on the Asian black market.) But Jans finds no evidence that poachers have ever been a problem in Treadwell's stomping ground of Katmai National Park, which is busy with bush planes, park rangers and boats.

This only adds to the complexity of Treadwell's legacy. As many naturalists quoted in these pages observe, by habituating bears to his presence Treadwell arguably did them a disservice. Bears that don't fear people are more likely to meet a bad end. Treadwell's death makes this much clear, as park rangers investigating the scene shot two bears that were protecting their remains.

Part of why Treadwell's story is so fascinating isn't just the overload of tragic irony. Much like Chris McCandless of Jon Krakauer's Into The Wild, Treadwell was an expatriate from middle-class America whose death unleashed a torrent of "I told you so" scorn, especially in Alaska.

Among grizzlies, Treadwell made an authentic life that he couldn't find in more conventional settings. To justify this lifestyle, he often distorted the truth and adopted an insufferably self-righteous messiah complex that was grounded more in psychology and self-interest than reality.

Americans are encouraged to dream big dreams, but most of us fall prey to the demands of the practical: kids, mortgages and basic cable. Nevertheless, our iconography celebrates a wild America.

Treadwell was hardly noble, certainly misguided and in some ways even selfish. But he lived life on his own terms, without apology. He basked in a wilderness few ever experience. And it wasn't always a picnic. Joel Bennett, a nature photographer who logged countless days with Treadwell, asks the $800,000 question:

"Think of Tim out on that coast, hunkered in a leaky tent, always wet or damp, no fire to dry clothes or cook on, bug-bitten, living on peanut butter. Alone most of the time, no one to talk to - and this was a guy who loved company . . . Day after day, weeks at a time, season after season for thirteen years - what sort of a man would do this?"

Perhaps one hungry for something greater than what so many of us work so hard to achieve: stability, comfort and respectability. What Timothy Treadwell accomplished for himself, before his gruesome end, was no easy walk. What he accomplished for "his bears" remains a mystery.

John Dicker's book "The United States of Wal-Mart" was released this month from Tarcher. He lives in Denver.