Kelsey knows the reactions his name can provoke among Utah's backcountry set. He seems to take a pirate's pride in the fact that over the years, several of southern Utah's national parks -- including Zion and Canyonlands -- have pulled his titles from visitor center shelves. "The parks want to have editorial control of what appears in the guidebooks they sell," he said. "I'm not about to agree to that. My books are kind of like the unauthorized, unsanitized versions."

My own adventures with Kelsey's guides are punctuated by a single ill-fated trip 16 years ago. As freshmen at Fort Lewis College in Durango, Colo., two friends and I followed Kelsey's descriptions into a rugged canyon near Green River called the Lower Black Box. We entered the main gorge and found the early-October flow of the San Rafael River cold and swift. The canyon steadily grew narrower and deeper, and soon we emerged in a section jammed with floating logs and large chokestones covered in slippery mud. In spite of 90-degree temperatures, our good physical condition and handy inner tubes, we were no match for the chilling combination of water and shadow.

Halfway through, I began slurring my words and shivering violently. We found a sandbar, and I put on my long pants and draped a towel over my shoulders for warmth. The shivering did not stop. A streak of sun illuminated what appeared to be a possible exit route. We cursed Michael Kelsey and started up.

After a half-hour of tense climbing, we reached the top and the warmth of the rim and discussed what had gone wrong -- which is to say, we deconstructed the book. Where was the information about the floating logs? The warnings of hypothermia? The caution about the current that held you like a vise against the massive stones? If the sky had rained frogs, or even just rain, we'd have blamed Kelsey for that, too.

I realize now that we had entered the Lower Black Box ignoring clear signs of danger -- too late in the year, too much water -- and lacking a clear understanding of the inherent risks. But even now, it is difficult to blame all our problems on our own poor judgment. Over the years, as canyoneering has becoming increasingly popular, our misadventures have been repeated by dozens of others. These stories carry a typical refrain: inexperienced hikers led astray by Kelsey's route descriptions.

I have watched most of this from afar. For the better part of the last decade, the concrete and steel canyons of New York City have been morose surrogates for the sandstone gorges of southern Utah. Yet I find myself pulling Kelsey's guides from my shelves as frequently as ever. At a certain level, they offer a visceral link to landscapes deeply etched in the soft stone of my memory. But it's more than that: Unlike any other guidebooks I have encountered, Kelsey's books exude a strange -- almost radioactive -- motive force; they quite simply make me want to "go." My desire to better understand their seductive power has become something of a subconscious itch. Perhaps this is why, this past June -- disregarding all posted warnings -- I decided to enter another one of Utah's deep, dark, watery places -- this time in the company of Michael Kelsey himself.

I crawl from my tent at 7 a.m. The sun zaps my face as I boil water for coffee. Kelsey is already awake, sitting quietly on the tailgate of his Jeep Patriot, which he has ingeniously transformed into a camper and support vehicle. Every inch of free space in the truck is stuffed with gear -- climbing rope, water jugs, sunscreen, daypacks, maps, sleeping bags, tattered copies of his various books. He has removed the passenger seat and rear seat and fitted it with a plywood platform and a small mattress. He prefers the truck to a tent, he says, because of his grueling schedule -- a week on the trail followed by a week at home in which he madly transcribes the handwritten notes from his backcountry rounds.

Kelsey relays the weather forecast: clear and hot, ideal for a descent into the Black Hole. He laces up a pair of running shoes, his trademark desert footwear, which he buys used a size too large and stuffs with thick insoles for greater shock absorption. We are in no hurry. Best, he says, to let the air warm before immersing ourselves in the cold water in the depths of the canyon.

My decision to defy the bullet-riddled warning at the edge of White Canyon is not entirely blind. My knuckles and shins bear fresh scrapes from the "warm-up" hike we'd taken the previous day through Blue John Canyon, a tangle of beautiful, challenging slots near Hanksville. As we clambered, crawled and stemmed through Blue John, I looked on in awe as the near-septuagenarian negotiated chimneys and massive chokestones with Spider-Man-style acumen. The Blue John complex is perhaps best known as the place where Colorado hiker Aron Ralston was trapped for five grueling days in May 2003. To escape, Ralston had to amputate his lower right arm, which had been pinned under an 800-pound boulder. Kelsey says he was contacted recently by Hollywood filmmakers working on a movie about Ralston's ordeal. I'm not surprised when Kelsey tells me that the filmmakers said that Ralston was toting a copy of his canyon guide.