Living in the temperate rain forests that run along the North Coast of California are the tallest species of tree on earth — Sequoia sempervirens, better known as the redwood. Today, the tallest redwoods are between 350 and 380 feet in height and some, specifically the redwood titan, which is larger in mass, can measure up to 30 feet in diameter. Botanists do not know the ages of these “blue whales of the plant kingdom,” as Richard Preston, author of “The Wild Trees,” describes them; however, they suspect that the oldest living redwoods could be 2,000 to 3,000 years old.

     In the mid-nineteenth century, the redwood forest occupied approximately two million acres of virgin, old-growth forest. With the introduction of steam-powered logging machines and twentieth-century inventions such as gasoline-powered machinery, the old-growth forest became victim to clear-cutting operations by timber companies who’d purchased large tracts of forest. Nearly 96 percent of the primeval redwood forest was felled.

“What is left of the virgin redwood forest is like a few fragments of stained glass from a rose window in a cathedral after the rest of the window has been smashed and swept away,” Preston writes.

Surprisingly, many of the remaining forests have never been explored and their redwoods have never been “discovered.” (Discovery of a tree does not mean that a tree has never been seen before; it means that no one has apprehended its size or measured it.)  A kind of topsy-turvy logic applies to the redwoods: because they are so immense — their tops rising so high in the sky that it’s almost impossible to see them from the ground — they’re often overlooked. Also, there has existed the belief among biologists that the redwood forest canopy was “unreachable” (a redwood’s lowest strong branch may be 250 feet above ground level) and “empty of life other than the branches of the redwood trees.”

     Nothing could be further from the truth. Clearly though, this claim could not be made without verification, and the only way to get that proof was to go skyward, to climb up 36 stories into the tops of these tallest of trees without perishing and take a look at what’s up there. “The Wild Trees” recounts the incredible story of the very first climbs into undiscovered redwoods, the majesty and near-unimaginable intricacy of these trees and the wide-ranging biodiversity found in the humungous redwood canopy — hemlock trees, huckleberry bushes, rhododendrons, bonsai laurel trees; a species of the wandering salamander that biologists believed could only live on the forest floor, yet was spotted at 305 feet.

     The book is a gripping adventure saga — its first two chapters are thrillingly addictive — but it is also the story of the climbers and their enthusiasm and dedication, their foibles and triumphs, their reasons for risking everything to enter this mysterious labyrinth. This is undeniably a story of passion and daring, as the book’s title declares, and Preston captures this essence with the precision of an accomplished teller of tales.

     “The Wild Trees” has five main players: Stephen C. Sillett, professor and canopy scientist at Humboldt State University in California; Marie Antoine, botanist and lichenologist at Humboldt State University; Michael Taylor, tree discoverer extraordinaire; Preston, who is a trained tree climber and author of the Dark Biology Series, which comprises “The Hot Zone” (1994), “The Cobra Event” (1997) and “The Demon in the Freezer” (2002); and the wondrous redwoods.

     Preston introduces us to Sillett when he is a 19-year-old junior at Reed College in Oregon in 1987. He is backpacking in California’s Prairie Creek Redwoods State Park. Sillett had never before seen a redwood, and he was “keyed up.” He finds an intriguing-looking redwood and, on impulse, mounts it. Sillet’s ascension becomes a watershed in redwood exploration.

     “Well into the last decade of the twentieth century,” Preston writes, “the redwood forest canopy . . .  was one of the last unseen realms of nature on the planet. Nobody had entered the redwood zone above the level of the ground, except for . . .  Stephen C. Sillett, who had nearly gotten himself killed there.”

     We first meet Marie Antoine in 1980 at the age of five. She is climbing a balsam fir 40 feet above the ground on Treaty Island in her native Ontario, Canada. And, Michael Taylor comes on the scene at age 20. Coincidentally, it is 1987, and he is a junior at Humboldt State University. He’s touring the Tall Trees Grove in Redwood National Park looking at the then-tallest tree in the world, the Libbey Tree.

     A few months later, during another visit to the Libbey Tree, Michael thought it “looked kind of scrawny.” Michael had been “obsessed” with redwoods since childhood, and his “sixth sense” told him that he’d seen taller trees. “He had a strong feeling that the most inaccessible parts of the redwood forest along the North Coast [of California] had never been thoroughly explored. The world’s tallest living thing was out there, somewhere, perhaps hidden in a lost valley. He could feel it. . . .  He wondered if he could find it.”

     Taylor sets out on his quest guided by a fierce determination. He crosses paths with Sillett and Antoine, and the “threads of chance and desire that join us into a world of human experience,” beautifully put by Preston, entwine the trio into an unbeatable team of redwood specialists. Preston connects with them to chronicle their amazing journeys into nature’s “unexplored Grand Canyon of botany” and he accompanies Sillett and Antoine on many of their death-defying climbs. (Preston diverges from his redwoods narrative to write about his tree-climbing exploits in New Jersey and Scotland. These passages interrupt the book’s continuity and might be better placed as an afterword.)

     “The Wild Trees” has the power to change how we look at nature and its endangered ecosystems. Read it. You will be awe-struck by the climbers and the “lost worlds” they discover and aim to preserve.