OUTDOORS : WALKING ON THE WILD SIDE : Colin Fletcher, Grandfather of Backpacking, Sees Need for Change

Colin Fletcher has traveled the world and into himself, recounting his findings along the way.

After years of leading readers across steaming deserts, through moonlit meadows and up wind-swept mountains, there is one animal he has come to fear: man.

“Once you have walked for a quorum of years . . . you accept, with more than just your intellect, that man is an animal,” he writes in his new book, “The Secret Worlds of Colin Fletcher.” “A very special animal, for sure, but still an animal.”

And because man is wreaking havoc with other species, Fletcher has reached a jarring conclusion he expects will shock armchair hikers who know him as the grandfather of backpacking.

What this planet needs, he says, is a plague that would kill off most of the human population and get it down to one or two billion again.

“Theoretically, a plague would do wonderful things to the planet,” he said in an interview.

Oil spills and strip mining would end, he said. Acid rain would abate, the ozone hole would shrink and disappear, lost rain forests would return.

This is an older and less carefree Fletcher than the one who introduced many Americans to the pleasures of the backcountry in “The Thousand-Mile Summer” 25 years ago.

His new book is his latest testament to the joys of walking. It meanders off on solitary jaunts through unnamed, untamed locales, extolling Fletcher’s familiar philosophy that nothing stimulates clear thinking like a wilderness walk.

But these secret worlds are meant more to be analyzed than camped in.

“I’m not really interested in encouraging people to get out there,” he said. “I want to change their views of the world.”

Fletcher, 67, lives with a foot in two worlds in the far outer reaches of the San Francisco Bay area--”shruburbia,” as he calls it. He guards his seclusion with the same ferocity he once displayed in leading a successful fight against local land developers, granting an interview only after extracting a promise that his hometown is not identified.

A decoy name is on his mailbox, and a crudely lettered “Beware of the Man!” sign warns visitors who dare approach his front door. The gruff Welshman has been called the J.D. Salinger of the high country.

Met on his own terms, however, he is hospitable, sharing anecdotes and trail mix with a visitor as red-tailed hawks soar above the tree-covered valley his home overlooks. Thick, black-rimmed glasses combined with a white beard give him an owlish, scholarly look, but he has sturdy legs and robust energy.

Fletcher inherited a love for walking from his mother, who especially liked walks in the rain. His first experience with a backpack was as a commando for the Royal Marines in World War II. The yen for writing surfaced later, when he spent five years in East Africa, mostly as a farmer, and wrote 70,000 words of an “awful” novel that has never been published.

After three years in Canada as a construction worker and prospector, among other jobs, he moved to California in 1956 and hit upon the idea of walking the length of California from Mexico to Oregon. The route took him across the Mojave Desert and Death Valley and up the Sierra Nevada range to wide acclaim with “The Thousand-Mile Summer.”

The tale of a wilderness trek was the first of its genre, but it happened almost by accident.

“The main reason I did ‘The Thousand-Mile Summer’ was to decide whether to marry the woman I was living with,” he said. “I got the idea in the middle of the night.”

Results were mixed: The two were married shortly after the walk in 1958 and got a divorce, Fletcher’s second, within months (he now lives alone). But he had developed his trademark as a writer.

In 1963 he undertook another solo trek, becoming the first person known to have walked the length of the Grand Canyon within the rim. The trip was the subject of “The Man Who Walked Through Time.” He sealed his reputation as a premier walker-writer in 1968 with the first edition of “The Complete Walker,” a mostly how-to book that became the backpacker’s bible.

“The Winds of Mara” and “The Man From The Cave” took the nature exploration theme further.

In all his books, he provides what he calls “great, granular detail” about camping. A squirrel rasps up a ponderosa pine, the pot on the stove mutters and a breeze flows down the canyon as Fletcher deliberately sets up camp with us before snuggling into his sleeping bag--a sort of backpacking play-by-play for less adventuresome readers.

Today he admits it’s more difficult to convey a sense of wonder about his other world.

“I’m not young any more,” he said. “I’m no longer rich with the rewards of inexperience.”

Yet, Fletcher is going on a six-month river rafting trip, the destination--of course--a secret. Even though he believes the green world he loves is being ruined, he doesn’t intend to sit by harrumphing idly while it decays.

Not yet, anyway.

“Well, all right, maybe man had to be stopped . . . but that did not mean that I, personally, must bang or whimper my way out,” he writes in “Secret Worlds.”

“I could still give myself up--sometimes, anyway--to enjoying the world’s human joys: making love, listening to Beethoven conducted by Furtwangler, executing a perfectly disguised backhand drop shot from the baseline.”

And walking, no less boldly, in search of old truths and new adventures.