"The good people of Green River City, Wyoming, turn out to see us start. We raise our little flag, push the boats from shore, and the swift current carries us down."

Thus did John Wesley Powell, the first white man to ride the Colorado River rapids through the Grand Canyon, begin his expedition journal in 1869.

A bit more than a century later, Edward Abbey's book takes us on another trip down the Colorado, down other rapids, and along other rivers of the mind and spirit. His collection of essays and Thoreauvian journals documents the physical, spiritual and emotional change that has quite reshaped America in the relatively brief time since Powell launched his boats.

It is a change that Abbey laments. He must search for the natural presences Powell took for granted, and he tells us again and again that the price of the Industrial Age has been high to the point of peril. When Powell rode the rapids, he was watched only by Indians and hawks. So mysterious was his journey that he was declared dead when he failed to emerge from the canyon at the appointed time. He had what Abbey would surely consider the enviable pleasure of reading his own obituaries when he finished the voyage.

Abbey's river expeditions are not explorations, but escapes. He takes to the wilderness to retain his humanity, to assert his freedom, and, with the eloquence of his writing, to help us perceive our humanity, to persuade us to establish a more sensitive relationship with the natural world. It is that relationship, this deceptively ardent essayist tells us, that is pivotal to our fulfillment and our freedom.

". . . one relic of our ancient and rightful liberty has survived" (over the industrial decades since Powell), he writes. "And that is--a walk into the Big Woods; a journey on foot into the uninhabited interior; a voyage down the river of no return . . . if we allow the freedom of the hills and the last of the wilderness to be taken from us, then the very idea of freedom may die with it."

The metaphysics--the capitalized "Big Woods," the "river of no return"--are part of the uniquely Abbey dimension. Like every fine writer of the natural world, he records what he sees with his mind's eye as well as the experience of his senses. He tells us how the sun slants on a canyon wall-- and tells us with crystal images--while he also comments on the asininities of the Bureau of Land Management.

But there is something more--a something that moves Abbey toward excellence, that grants him the right to be considered an exceptional member of the growing community of writers who have taken what's known today as "environmental journalism" as their particular province.

Edward Abbey has a fine humility; the wires of ironic humor that he weaves through each of the 19 essays and reports of this memorable book and his charming modesty prevent him from preaching. He doesn't tell us what we should or shouldn't do to "save" our environment. He writes with zest and passion about his voyages down the rivers of his natural world, and that becomes that. Our response is not dictated, but left to us to decide.

Abbey himself sets up this distance. He is there, living and breathing in his writing, but he is wary of encouraging intimacy. Like one of the tall saguaro cactus that grows in the deserts of his home near Tuscon, he protects himself with barbs that turn up as delightful surprises in the mainstreams of his prose.

"Young dancers in a classroom; an old sculptor hacking at a block of apple wood . . . a solitary fly fisherman unzipping his fly," and "The vulture flaps into the shelter of the trees, swearing quietly" . . . or, "another day, another dolor." Abbey's irony needles, it deflates temptations toward pomposity. It is the badge of humility the man wears as he takes us with him on trips down rivers, on his solitary journeys to the Sonora, into the crevasses of Alaska's blue glaciers, through the canyons of the Apache, and into the ghost towns of the American West that he loves with such intensity.

It is the way he balances that intensity with evidence of his own humanity that makes Abbey such an eloquent and entertaining defender of natural truths. It is what makes him an exceptional environmental writer. It is what allows him to say: "We drift on together . . . a human family bound by human love . . . Loving one another, we take the sting from death. Loving our mysterious blue planet, we resolve riddles and dissolve all enigmas . . ." and have his readers recognize it as a truth, not trite. It is Edward Abbey's own genius that creates the space that can convincingly sustain such observations.

His needles protect his soul. Like the saguaro, the inner Abbey stores bright truths that can quench our thirst for hope.

"Be of good cheer," he writes, "the military-industrial state will soon collapse."

Be of good cheer, readers of Down the River.