Just west of Tucson is a fairy-tale oasis where ducks waddle in a desert, humans improve the biodiversity, and leafy fig trees coexist with spiny cacti.

by Gary Paul Nabhan

The winter sun hangs low over the Arizona hills near the border with Sonora, Mexico. It is January, but the air is warm and musky, and the sky is clear except for the 11 ravens soaring, cajoling, and squawking overhead. As I catch my breath after running to the crest of a pale granitic hill, my vision opens to a larger, more colorful world.

There, stretching clear to the volcanic ranges on the western horizon, is an astonishing mosaic of pitch-black cedar, tan granite, golden sand, buff silt, and ghostly soda flats: Organ Pipe Cactus National Monument.

Organ Pipe covers 516 square miles of the most pristine part of the Sonoran Desert on either side of the U.S.-Mexican border. It is world renowned for its forests of giant cacti and ancient ironwood trees. Immediately below me, splashes of verdure circle a pond in a place where it seems no pond belongs. Yet towering cottonwood trees confirm that, yes, this pond does belong. Seven artesian springs seep up a fault that runs along the base of these hills, creating the minor desert miracle called Quitobaquito oasis.

I have spent dozens of dawns and dusks at Quitobaquito during the past quarter-century, censusing the birds and plants that thrive here. This time, I'm amazed to find a ring-necked duck -- a duck in the desert! And though it's the depth of winter, a violet spiny aster and a yellow jackass clover plant are in full flower. No matter how many times I've visited these spring-fed wetlands, I'm always in for a surprise.

Once, at twilight, as I reached the top of the ridge above the Quitobaquito springs, four mule deer stepped across the road in front of me after drinking at the oasis, the only pond for 20 miles in any direction. Early one spring, I watched a Costa's hummingbird defend desert lavenders in its breeding grounds against migrating interlopers. Another spring, I was the hapless interloper. A border patrolman mistook me for a drug runner, holding me at gunpoint until he was sure that I was carrying only binoculars and a field guide. He could not believe that I had driven dirt roads for 25 miles in the dark to watch birds at sunrise; I was astounded that he did not know Quitobaquito as a magnet for native wildlife such as javelinas, deer, mud turtles, a multitude of birds, and "desert rats" -- human desert lovers.

Most of Organ Pipe's 227 species of resident, migrant, and vagrant birds have shown up at Quitobaquito at one time or another. Its wetland, riparian, and desert-scrub habitats support the highest density of breeding birds in southwestern Arizona, with as many as 470 pairs on 100 acres. When I helped several colleagues survey the flora of Quitobaquito, we found that the oasis harbored 271 plant species -- 45 percent of those recorded in Organ Pipe -- though it accounts for just 3.5 percent of the monument's area. That's roughly one-third of all plant species growing within the surrounding 5 million acres of gran desierto, a place the writers Edward Abbey, Doug Peacock, and Chuck Bowden have affectionately called the Big Empty.

Quitobaquito is a place of intermingling natural melodies. Artesian springwaters bubble up to the barren alkali flats. Hot, dry winds rustle the leaves of ancient cottonwood trees, where Brewer's blackbirds roost and call raucously to one another. At night you can hear the whir of the wings of bats swooping down to snatch insects over the pond, as poorwills call from the hills above you.

Quitobaquito's natural sounds merged with cultural melodies over the centuries, as native voices rose up around desert campfires. The site was occupied by indigenous people from about 8,000 years ago until 1957, when the last Hia C-ed O'odham resident gave up his people's claim to ranch and farm there. Other tribes came to these springs to camp, trade, and refresh themselves while on their way down the treacherous Camino del Diablo, or while making a salt pilgrimage to the shores of the Sea of Cortés. They chanted here while ritually cremating the bones of bighorn sheep and drank sacramental cactus wine to entice the summer rains.

Native Americans also left an imprint on Quitobaquito's biological diversity. Through occasional flood irrigation of nearby fields and flats, O'odham farmers provided habitat for wading birds such as killdeers. Their burning of cattails and rushes during the dry season opened up nesting and refuge sites for rails and coots. Their custom of transplanting cottonwoods and introducing plants such as figs and pomegranates for shade, food, and fuel provided roosts for hawks, flycatchers, and orioles. My research team (I am director of conservation biology at the Arizona-Sonora Desert Museum) has found that since 1957, when Native American farming and burning traditions were abandoned, the oasis's biodiversity may have actually declined. At least six native wetland plants have been lost, and five bird species may have stopped breeding there.

Fortunately, resource managers in the National Park Service, which operates the monument, are willing to experiment with some of the O'odham practices, realizing that humans do not inevitably deplete local diversity but can sometimes enhance it.

Organ Pipe Cactus National Monument is one of the few UNESCO biosphere reserves in the United States that truly involve nearby communities in multicultural education, conservation, and participatory research. (UNESCO stands for the United Nations Educational, Scientific, and Cultural Organization.) It has been assisted in this cause by the nonprofit, grassroots International Sonoran Desert Alliance.

Activists from both countries are working to establish a Sonoran Desert National Park, which would include Organ Pipe; the Cabeza Prieta National Wildlife Refuge, to the west; and two newly protected areas in Mexico, the Sierra el Pinacate and the Colorado River Delta national biosphere reserves. The park would safeguard 4.6 million acres in all, making it the largest protected desert anywhere in the world.

A protected Sonoran Desert might also ensure the long-term survival of the imperiled desert bighorn sheep; the endangered desert pupfish, Sonoran pronghorn antelope, lesser long-nosed bat, and flat-tailed horned lizard; and other wildlife. These animals are suffering from what ecologists call boundary effects: Wherever their range extends beyond protected habitat fragments and into adjacent areas -- where pesticides, herbicides, and woodcutting persist -- they are vulnerable to the threat of extinction.

I support such conservation initiatives, but part of my enthusiasm for the area is purely hedonistic. Twenty-four years after my first visit there, I still return to Quitobaquito as frequently as I can. Is it the mere presence of water that lures me there, or the excitement of spotting rare species such as desert pupfish and Thornber's fishhook cactus?

My guess is that I feel more a part of this place than any other on the planet. My first child was baptized in Quitobaquito's springwaters. I have crawled under its bushes to survey its biota and sat by its rivulets while recording oral histories from elderly Indians who once lived beneath its trees. I have tasted its cactus fruit and skinny-dipped in its pond. It has refreshed and renewed my life in ways I can't explain.

Perhaps I am just one more of the anomalous aspects of the history of Quitobaquito and the gran desierto, a Lebanese-American who has adopted a desert home far from the country of his Arab forefathers. And yet, I am no more anomalous than the desert oasis itself, with its Mediterranean figs and pomegranates growing next to native capers and cacti. Quitobaquito's natural and cultural legacies are full of juxtapositions: wet and dry, sacred and profane, native and exotic. And that's why I like it -- I see myself reflected in its waters.

Gary Paul Nabhan is working with other scientists and local activists to establish a Sonoran Desert National Park.

Being There: Organ Pipe Cactus National Monument

Organ Pipe Cactus National Monument, founded in 1937, covers 516 square miles of the most pristine part of the Sonoran Desert. West of Organ Pipe lies Cabeza Prieta National Wildlife Refuge; across the Mexican border is the Sierra el Pinacate Biosphere Reserve, an almost lunar landscape of volcanic origin that is juxtaposed with the largest sand sea in North America. West of the Sierra el Pinacate sits the Upper Gulf of California and Colorado River Delta Biosphere Reserve.

Getting There: Organ Pipe is roughly 150 miles from both Phoenix and Tucson. It can be reached by taking Highway 85 south from Gila Bend, Arizona, or Highway 86 (Ajo Way) west from Tucson.

Weather: One part of the Sierra el Pinacate suffered 34 months without measurable rainfall, so you needn't bring an umbrella -- unless you're there in midsummer, when abundant sunshine raises the air temperature as high as 118 degrees Fahrenheit. The ground gets as hot as 165 degrees.

Hiking: The entrance fee to the monument is $4 per vehicle. At the visitors' center (520-387-6849), 35 miles south of Ajo on Highway 85, park rangers will answer your questions about local wildlife. The Bull Pasture Trail takes hikers into the uplands of the Ajo Mountains. Segments of the ancient salt trail to the Sea of Cortés run by Quitobaquito and Bates Well, near the monument's northern boundary.

Camping: Most of Organ Pipe is officially designated as wilderness, and camping permits are given by section so that visitors are dispersed widely enough to ensure a true wilderness experience. Backcountry permits are free but must be obtained in person at the visitors' center. Car camping is allowed in Organ Pipe at two designated campgrounds, on a first-come, first-served basis. Reservations for group camping (about $20 a night) can be obtained by calling the center. Camping is also available on the adjacent public lands, but per-mits are required for Sierra el Pinacate and Cabeza Prieta.

Wild Things: From desert tortoises and Gila monsters to leaf-cutter ants, javelinas, and coatimundis, Organ Pipe has a tropically derived desert fauna that can be seen few places outside Mexico. Cacti such as organ-pipe, senita, and Sonoran night-blooming cereus reach their northern limits in or near the monument. More than 400 bird species have been recorded in Organ Pipe, Cabeza Prieta, and the two Mexican biosphere reserves.

Rare Finds: Keep your eyes peeled for Sonoran pronghorn antelope, members of a subspecies with fewer than 500 individuals remaining. The rare acuña cactus is protected here and nowhere else. Desert pupfish are easy to spot in Quitobaquito's springs and rivulets.

Food and Lodging: Ajo, Arizona, has several motels and two bed-and-breakfasts: the Guest House (520-387-6133), which charges $79 for a double with full breakfast, and the Manager's House (520-387-6505), which charges $75 to $105 for a double with full breakfast. For food, I prefer the restaurants in Sonoyta, Mexico, particularly Lupita's Tacos.

Learning More: The Arizona-Sonora Desert Museum (520-883-1380), 14 miles west of Tucson, offers an orientation to the entire desert borderlands. Its web site http://www.desertmuseum.org/ gives an overview of natural resources and ecotourism opportunities. La Ruta de Sonora Ecotourism Association (800-806-0766), a multicultural alliance, provides tours and talks.

-- G. P. N.