The height of adventure is sometimes only 350 feet. With best-sellers like The Hot Zone and The Cobra Event, Richard Preston has made a career scaring readers silly about the gruesome dangers of microbes and pernicious germs. In his new book, Wild Trees: A Story of Passion and Daring, Preston shifts gears to larger subject matter: the Redwood forest canopy. Preston infiltrates the subculture of this country's newest breed of adventurers: those locating, exploring, studying, and climbing the world's tallest trees -- the ancient redwoods of the northwest that stretch over 35 stories high. "So many incredible things happen in our world that are never noticed, so many stories never get told," says Preston. "My goal is to reveal people and realms that nobody ever imagined." Wild Trees is all true, and reads like a page-turner. It follows the lives of three tree-climbing pioneers, from adolescence until they meet and collectively turn the arboreal world upside down. Stephen Sillett was so impassioned by tree climbing as a youth, he was barely able to concentrate on schoolwork, but now teaches redwood canopy science at Humboldt State University (and is always searching for the world's next tallest tree). Marie Antoine spent a good chunk of her Ontario childhood outdoors and up in trees, and now lectures in the botanical sciences at Humboldt State University. And Michael Taylor, the former grocery clerk and long-time amateur naturalist and explorer, shows that scientific knowledge does not come solely from Ivory Tower researchers. Wild Trees takes place mostly in the thick, tangled rainforests of northern California, where entire basins remain unexplored. (In keeping with the wishes of land administering agencies, Preston does not reveal the locations of most tall trees he discusses.) Naturalists will enjoy the discussion of the flora and fauna found in the fragile canopy ecosystems, and armchair explorers will certainly eat up the adventure elements. But where the book excels is in getting into the minds of the climbers. It reveals a level of desire and passion few are privy to. The tree-climbing community featured in Wild Trees is not a bunch of Evil Knievel clones seeking their next adrenaline shot; they're simply a close-knit enclave of researchers dedicated with unusual ardor and obsession to their science. Wild Trees eventually heats up into a love story when two main characters, Sillett and Antoine, unite in matrimony. Their canopy wedding scene is the book's crown jewel. Bride dangling 300 feet above the ground, decked out in a long, flowing wedding train woven with real lichen. Groom twisting and turning on a rope beside her, garbed in rain gear. And a geologist cum minister standing on a high-up outstretched redwood limb, relaying the vows with one eye gazed downward for safety. "It was a sunny day, with light winds," writes Preston. "Antoine and Sillett left their trees and moved towards each other in space, advancing along the rope strung between the spires. Her wedding veil, decorated with lungwort, floated around her in the wind. They met in the space between the trees and exchanged the rings, and they began to exchange private wedding vows. They were now hanging on the middle of the rope, floating and bobbing in the breeze and the bride's veil was streaming. They had discussed what would happen next. Sillett wrapped his legs around Antoine, and in that way he carried her across the threshold of air to the altar, pulling her along the rope." For their honeymoon, the couple journeyed to Australia to, you guessed it, climb tall trees. In one fretful scene, the climbers top out on a 30-story redwood named Telperion, when a storm hits, deluging them with torrents of rain and slapping winds. Fearful for their lives, they shimmy down in dire conditions. Soon after, Telperion tumbles, tossing mud splats six stories in the air, and serving as reminder as to the inherent dangers of extreme tree climbing. Preston discourses in great detail about how to physically climb trees and what equipment to use. This may prove tedious to some readers, but rock climbers may find the similarities and differences between their sport and Preston's fascinating. And writers rarely care to become part of the story, but Preston makes an exception with Wild Trees, refusing to play the role of stodgy chronicler purveying his tale from afar. Preston learns the art of Redwood climbing, and spends a few chapters in the canopy with Sillett. He also accompanies Sillett on an expedition to measure the 379.1-foot Hyperion tree, the world's tallest living object. (The world's largest living object is supposedly a three-square-mile edible fungus living underground in Oregon.) Preston is among the great living non-fiction writers, with clean and easily readable prose and stories that always engage. He's mastered the art of creative non-fiction; applying elements of the novel (pace, dialogue, and descriptive detail) to hold the reader's interest in a true story. With Wild Trees, he manages the unthinkable: a book on tree climbing that is virtually impossible to put down.