The Secret Life of Emptiness : SPIRIT OF THE AMERICAN SOUTHWEST, By Diana Kappel-Smith (Little Brown: $22.95; 262 pp.)

An abandoned city, a destroyed village, condemned ranches, sand dunes, vanished rivers and lakes and seas--these are the puzzles of emptiness and absence that Diana Kappel-Smith confronts in “Desert Time: The Spirit of the American Southwest.”

The desert, and those few remaining creatures who have adapted to its extremes, are what defines the Southwest for Kappel-Smith, and by that she means the non-urban desert--a far quieter and emptier place than the urban centers she flies in and out of and drives through during the 18-month quest recorded in this collection of essays.

The emptiness of the desert is only an apparent emptiness, as Kappel-Smith’s skill as a writer lies first in describing the feel and taste of scenes most people would view with a sense of desiccating agoraphobia, and then in populating them with rich and curious details of geology and natural and human history. She also reminds us that there are several types of desert: the term applies to Death Valley, the sand dunes of southern Colorado and even as far north as the arid lands of southern Idaho and eastern Oregon.

Southwestern deserts weren’t always as they are now, of course, and the hardy survivors from the lusher millennia represent only a fraction of the life that once roamed the vastness. Traveling far--more than 20,000 miles--both alone and in the company of her 13-year-old son Coulter, Kappel-Smith found islands of primordial desert, oasis and cave being encroached on by highways, off-road vehicles and hopeful subdivisions.

Especially in danger are desert inhabitants such as the sage grouse, which is now undergoing a fertility crisis, and the desert tortoise. “It would be good to know,” Kappel-Smith wonders, “why we cause most havoc with creatures most like ourselves, the largest predators and the most long-lived and social of beasts: the lions and wolves, gorillas and whales and elephants, and tortoises, too.”

Yet there are also successes. The bighorn-sheep population is on the increase, due in part to the efforts of organized hunting groups--the antithesis of the anarchistic desert “plinkers” who enjoy taking potshots at anything that moves. Another irony that Kappel-Smith presents us with is the fact that military reservations can make some of the best nature preserves, because they exclude ATVs, dune buggies and other scourges of the fragile desert ecology.

The human is a relatively new and insignificant player on the desert landscape, and even the oldest inhabitants, the Hopi and the southern Arizona Tohono O’odham, and the relatively young Navajo, whose villages and encampments Kappel-Smith visits, seem touched with the ephemerality that informs most poignantly the human enterprise, both grand and humble, where the sky is always so large. In her travels, Kappel-Smith introduces us to many desert characters, Native American and more recent arrivals, but they are all intermediaries, guides to what enthralls her: the emptiness, “the space to be away from other people’s judgment,” where one can seek out another piece of the puzzle of survival in an environment of extremes.

“Desert Time” invites comparison with Ian Frazier’s “The Great Plains,” a celebration of that other vastness on the eastern side of the Rockies, though Kappel-Smith’s somewhat reticent essays are closer to those of Barry Lopez, who also rather says too little than too much. You come to trust her company and to savor her observations; she is the sort of guide who gestures at what you would otherwise step across--or on--without noticing. She calls her collection “an introduction to particulars.” These she infuses with radiance.

(Her lack of a central thesis, the pursuit of which might have given the book more narrative drive, is a minor quibble; and she says right off that the book will “not attempt generalities.”)

While Kappel-Smith chronicles the many man-made dangers to the desert, throughout this book, she emphasizes that man’s influence on the land “won’t mean much in the general scheme of things. We think too much of ourselves. If dried lakes and deserted cites aren’t enough to convince us that climates change anyway, if ancient reefs heaved into the cores of continents aren’t enough to tell us that they always have; then nothing would ever be enough to humble us into perspective.”

But while the environmental havoc we wreak may not harm the desert in nature’s grander scheme, Kappel-Smith points out that it would eliminate a deeper source of “balancing wisdom.” Thus, she concludes, “Our sins against nature are sins against ourselves.”