The Taste of Cactus : MEZCAL <i> by Charles Bowden (University of Arizona Press: $19.95; 154 pp.) </i>

The question “Who cares?” is the first obstacle a reader is likely to face upon entering an autobiographical work by a relatively unknown author.

In the first pages of “Mezcal,” the question arises often, as Charles Bowden, the editor of Tucson’s City Magazine, tells us he was born in an old farm house, moved to Chicago at age 3, to the Southwest at 12 and that “speed has always been my addiction, and the velocity of things has yo-yoed me across the continent.”

Quickly enough, though, the details of Bowden’s life begin to resonate, and the question grows dim as familiar chords--electric guitar chords--gather volume.

Bowden’s fourth book, “Mezcal,” might be seen as a culmination. “Killing the Hidden Waters” (1977, University of Texas Press) was a scholarly examination of water depletion in the Southwest. “Blue Desert” (1986) and “Frog Mountain Blues” (1987, University of Arizona Press), although written in a politically engaged first person, were mainly straight-ahead journalism about the fate of the Southwest.

In “Mezcal,” though, Bowden drops the journalistic veil, exploring the ecology of his interior landscape at least as thoroughly as the changing scenery that surrounds him.

Fueled by assorted pills, marijuana and, as the title suggests, mezcal (the cheap but potent distillate of the agave cactus), Bowden’s self-reflective reportage of the 1960s waxes gonzo, plunging ahead at a bleary pace reminiscent of Michael Herr’s “Dispatches.”

One moment he’s a “dharma bum” rampaging through Mexico, the next he’s in Madison, Wis., building barricades against the Vietnam War as the aroma of tear gas and the Stones’ “Street Fighting Man” waft in the air. But it’s only when he finally grounds his addiction to the adrenaline rush of modern life upon the tranquillity of the natural world that he finds an original voice.

Back from a canoe trip in northern Wisconsin, Bowden steps away from a particularly cacophonous student demonstration and enters the garage where his canoe rests on a sawhorse. “I sit on the floor with an open bottle of wine, reach up and touch the curve of the prow.”

Grueling, thirsty hikes through the desert soon replace canoe trips as Bowden’s preferred method of calming the demons of civilization in his head.

As his understanding of environmental issues matures, Bowden develops a long-view fatalism about the turf where humanity’s instincts for self-preservation and self-destruction intersect.

Observing yet another irrigation project, he writes:

“It will fail, it always does. . . . Then the desert will return. . . . It will wake up--you can count on this--and make the women old and wrinkled, the men crazy with heat and defeat, the crops writhe with pain as the cells in the leaves scream for rain and the roots shudder at the touch of the salts. Experts will be consulted, recommend various schemes, and then fail. . . . I no longer have much to say about such matters.”

Joan Didion has written that “a place belongs forever to whoever claims it hardest, remembers it most obsessively, wrenches it from itself, shapes it, renders it, loves it so radically that he remakes it in his image. . . .”

Others--Aldo Leopold, Edward Abbey--have already staked inviolate claims on the Southwestern deserts. But Bowden owns the complex terrain where, like a mezcal-inspired mirage, the Sonoran sun-belt overlaps the gray convolutions of the American mind.

A farm-belt immigrant himself, he understands the new land rush. He realizes that “deserts speak to some deep need in modern people . . . .” But he also understands the lure of opposites.

“I have spent my life in cities and am intoxicated by the fierceness of such places,” he writes. “And I have always felt something missing that led me back to empty, wild places. I have been told that this is a romantic flaw in my character and in the character of my countrymen. I disagree.

“I think this is our character.”