ON A WARM JULY AFTERNOON I am going to see the mouth of the Rio Grande for the first time. Sixteenth-century Spaniards called the stream Río de las Palmas; the bright forest of palm trees around the mouth was a landmark for navigators of the Gulf. In good years, the lowlands surrounding those groves would be marshes teeming with shellfish and minnows hunted by ibis and herons stepping sprightly in the brine. But today, as I ride eastward on Texas Highway 4, the most striking features ahead are airborne white swirls of sand and salt. Decades of clearing for agriculture and development have isolated the last native sabal palms to a small Audubon preserve outside Brownsville, and most of the wetlands have gone as dry as chalk. The sprawling river delta has been reduced to a nearly barren, eroded strip of earth, and some residents of Port Isabel are having trouble breathing because there’s so much windblown grit in the air.

My guide is a pleasant man named Gilberto Rodriguez who grew up on a farm in Weslaco and now roams the lower Rio Grande as a watermaster specialist for the Texas Commission on Environmental Quality (TCEQ). In layman’s terms, Rodriguez is an unarmed water cop; he spends much of his time checking pump gauges on the Texas side, making sure none of its farmers are drawing more water than they’re allowed. For many Rio Grande Valley residents, the mere inference of such cheating sparks outrage, and Rodriguez tells me he often fears violence. “The hotter the water,” he reflects, “the more hostile people become.”

He is not referring to water temperature. Valley growers are livid over what they believe is Mexican theft of Rio Grande water in the northern state of Chihuahua. You might think the Rio Grande begins with snowmelt and rapids in the Rockies of Colorado and New Mexico and then marks the plains with graceful lines of cottonwood and willow as it claims its legacy as the Texas-Mexico border. Technically, that’s true. But these days, dams in New Mexico, the thirsty and sprawling border cities of El Paso and Juárez, and giant tangles of nonnative salt cedars strangle the Rio Grande’s once mighty flow by the time it enters Texas. In reality, the river’s headwater today is Mexico’s Río Conchos, which begins high in the Sierra Madres, crosses the Chihuahuan Desert, and revives the parent stream at Presidio and Ojinaga, above Big Bend. Roughly 50 percent of the water in the border stream now comes from the Río Conchos.

By terms of a 1944 treaty, two thirds of the Conchos flow belongs to Mexico; the remaining third is supposed to continue on to the United States. But in recent years, Mexico has amassed a huge “water debt.” Instead of regularly releasing Río Conchos water downstream, Chihuahua has stored it in reservoirs and put it to the use of its towns and irrigating farmers. Texas farmers believe that their way of life is being sold upriver, and they’re frustrated by the lack of action from the U.S. government. They calculate the loss to their fields at about 489 billion gallons of water and warn that the Valley economy could collapse. Their anger has embroiled Mexican president Vicente Fox in a domestic political furor that has soured relations with the U.S. Invoking the rhetoric of the war on terrorism, Texas agriculture commissioner Susan Combs, one of the farmers’ key political advocates, has called Chihuahua “a rogue state.” But the farmers’ frustration and vituperation is aimed not only at Mexico. The conflict has also embarrassed Governor Rick Perry and President George W. Bush.

A dwindling supply of water is an issue for every citizen of Texas, but few residents have as desperate a case as Rio Grande Valley farmers. They’ve suffered a dry spell in the past decade that rivals the legendary drought of the forties and the fifties that turned most of Texas into a federal disaster area. Because the groundwater is brackish, the Valley gets no help from aquifers; the Rio Grande carries all the water there is. Every drop of Conchos water is vital, but that spigot too has been all but turned off.

Nowhere is this reality more clear than at the mouth of the Rio Grande, which is further consumed by mats of water hyacinth and hydrilla. At the terminus of Highway 4, Rodriguez and I jostle from pavement to loose sand. It’s a pretty day at the beach. The white-capped waves are bright dark blue, and squadrons of brown pelicans fold their wings and smack beak-first into the surf, trying to catch dinner. Boca Chica, which means “small mouth,” has none of the glitz and development of nearby South Padre Island, but families are out fishing, splashing, building sand castles. Ahead, a portable light tower has been erected. That landmark, Rodriguez tells me, is Mexico. Parked on the beach, hood pointed toward the surf, is a green-and-white SUV marked U.S. Border Patrol. For hours on end two agents sit and stare at beachcombers and the Gulf.

The agents represent the increased vigilance of Homeland Security, but their presence here also marks the death of a river. The riverbank they’ve parked beside is now a land bridge. It is not unlike other strips of sand and shell that the tide and currents lay out in the Gulf’s endless construction of beaches becoming dunes becoming barrier islands. The difference is that this sandbar has obliterated a natural frontier between nations and left the mythic Rio Grande a tepid, stagnant shallow. It has too little push to cross the bar and reach the ocean.

On this day the pool trapped at Boca Chica looks blue enough, but its biological illness is indicated by crusts of salt that line the banks for hundreds of yards upstream and resemble icy slush. Freshwater inflow is an estuary’s lifeblood, but these days the Rio Grande has little of that to give. I watch some Mexican boys skimming the stagnant pool with fishing nets. One stands in the middle of the river, about a quarter of a mile inland, and the water comes no higher than his knees. “I have not brought you to the mouth of the river,” Rodriguez says with a slight smile. “I have brought you to the end of the river.”

THE RIO GRANDE’S RICH AND COMPLEX story has turned on many human events—the bravery of Mexican settlers on the lower river who refused to yield to Apache and Comanche Indians; the emergence of El Paso, whose citizens had constructed a bridge by the early 1800’s and made the city a gateway of immigration and trade; the coming of the first norteamericanos as beaver trappers in the highland river valley and farmer-colonists in Texas. But history’s most important bend of the river was the Treaty of Guadalupe Hidalgo, which ended the U.S.-Mexican War in 1848.

Until then, the Rio Grande had been a long but fairly ordinary stream on the Indian frontier. Mexico had lost its war with Texas in 1836 but refused to recognize the infant republic and in any case maintained that Texas’ border was farther north, on the Nueces River. But after American troops had overrun Mexico, sacked the capital, and imposed martial law, Mexican negotiators could not bargain from a position of strength, and the Hidalgo treaty established the Rio Grande as the U.S.-Mexico border from its mouth to the thirty-second parallel. Mexico watched Texas’ annexation become final and also lost all, or parts of, land that became California, New Mexico, Nevada, Utah, Arizona, Colorado, and Wyoming—a full third of its territory. Bitterness and resentment were planted in the Mexican psyche that simmer to this day.

The change in sovereignty transformed everything. The young state of Colorado, with backing from English investors, seized on the potential of Rio Grande agriculture and put its water to use in the San Luis Valley. By 1896, between 350 million and 500 million gallons of water a year were being lavished on farms in Colorado and New Mexico. The upstream farmers maintained that the water was theirs even if the river went bone-dry by El Paso. Mexican growers each year saw a decrease in water reaching the El Paso Valley. Fields withered and orchards died, and Juárez faced a shortage of drinking water.

To make matters worse, in 1897 another British-financed company, headed by a physician in Las Cruces, announced plans to build a dam near a big barren clod called Elephant Butte, 125 miles north of El Paso. The speculators promised flood control and more orderly distribution of the water, but Mexicans cried that they would be dried up, and boosters in El Paso claimed that a more rightful place for such a dam was in their city. The U.S. Secretary of the Interior embargoed construction of the dam. Congress held hearings. A lawsuit reached the U.S. Supreme Court. The matter remained unresolved for seven years.

Finally, an irrigation congress convened in El Paso in 1904. The feuding parties suddenly reached a stunning compromise: The United States would build the dam at Elephant Butte. Mexico was guaranteed 60,000 acre-feet of water a year which, most years, would be a small fraction of what would be available to the U.S. (An acre-foot is the amount of water required to flood one acre of land one foot deep—about 326,000 gallons.) Was Mexico steamrolled again by U.S. power? Was there a covert payoff? Or did Mexican officials just perceive self-interest in the dam? The thinking behind their concession is veiled in a dense murk of years, pride, and diplomacy, but whatever the explanation, the country was once again treated like poor and unwanted kin. The new treaty was ratified by the countries in 1907, and the dam was completed in 1916, effectively cutting the Rio Grande in two.

On the outskirts of Truth or Consequences, a town that changed its name in honor of the famous game show in 1950, the Elephant Butte Dam today holds about as ugly a lake as I’ve ever seen. No trees grow on the shores, the campgrounds and picnic tables are deserted, and only a few fishing boats are scattered about. Between the opaque blue water and the slopes of maroon rock and soil is a strip of ground that looks bleached.

“People call it the Bathtub Ring,” chuckles Steve Harris, a conservationist and river guide, who has joined me for a tour of the river north of Texas. The 54-year-old Harris organized his first whitewater trips in Big Bend in the seventies and now lives in Taos, where his company, Far-Flung Adventures, runs whitewater tours through the Class IV Taos Box. He’s passionate about the Rio Grande. He says the dark ground around the lake marks Elephant Butte’s historic waterline, and the pale strip below gauges the recent years of too little rain: “The lake was supposed to hold 2.2 million acre-feet. It’s filled up and gone over the spillway a few times. But after they built it, the first thing they got was thirty years of drought.”

A dry cycle and an unsightly dam are not the only things that have siphoned water from the Rio Grande. Tamarisk, or the misnamed salt cedar (it does carry salt, but it is not cedar), was brought from North Africa and Central Asia to the American plains in the nineteenth century to help stabilize riverbanks. With lacey, light-green foliage and a frail lavender bloom, a single tamarisk is not unattractive. But brakes of the pest brush are taking over the Rio Grande and many other rivers in the West. “They use twice as much water as the native willow and cottonwood,” Harris says. That is because they grow so thickly and spread so far from a river’s bank. Prolific tangles of the brush block the waterways and create bizarre wetlands in desert terrain, consuming much of the Rio Grande between El Paso and Big Bend.

Harris and I drive south from Elephant Butte, following the dam-released river on Interstate 25. In a while we cross the state line into El Paso. The riverbed here is paved and forbiddingly wired off by border security. We follow a road into an industrial strip just across the river from the Juárez slums. In cheerful contrast, the Hacienda Cafe adjoins a lot where historic markers stand. The owner, Chip Johns, walks out to greet us. He wears a cowboy hat, a big belt buckle, and sharp-toed boots. “Don Juan de Oñate came across the river right here in 1598,” he proclaims. “There were soldiers and priests, one hundred thirty families, seven thousand head of livestock. The first mares ever seen in Texas.”

It’s difficult to imagine such a pastoral scene at this site now. The population of Juárez and El Paso exploded past 1.5 million in the past decade, and the growth has not been pretty. Here, average rainfall is less than nine inches a year, and the abundant aquifers that were expected to help with the water needs have been diminished at an alarming rate. Meanwhile, the groundwater and the river have become increasingly polluted. By the early nineties, rates of hepatitis, tuberculosis, and dysentery in El Paso County were running three to five times the national average.

Just upriver from the Hacienda Cafe, the river’s bend toward the Oñate crossing is dominated by a large black complex, the infamous century-old Asarco copper smelter. Its American owners closed the smelter in 1999, citing low copper prices, but the TCEQ and the Environmental Protection Agency had beleaguered the smelter with repeated assertions of contamination. The day Harris and I arrive, El Paso evening newscasts blare a story that the EPA has found that much of the soil around the smelter—which is near downtown—contains high levels of lead and arsenic. Lawns will have to be dug up and trucked away in the emergency cleanup, and the groundwater is endangered. But beneath Asarco’s cracked windows and dormant smokestack, I watch boys from Juárez swimming happily in the river.

The Rio Grande, which Mexicans call the Río Bravo, is a treasured trout stream in Colorado. Its gorge outside Taos is one of this country’s most stunning natural spectacles and whitewater chutes. Just upstream from Elephant Butte, a wildlife refuge called Bosque del Apache swarms each fall with millions of migratory birds. But throttled by the Elephant Butte Dam and its irrigators, the Rio Grande is almost dead when it reaches El Paso and Juárez. Water released downstream from their punishment is mostly treated effluent. And then the tamarisk stakes its claim. Ensnarled by salt cedar, a 216-mile stretch of the Rio Grande from Fort Quitman to Presidio has been reduced to a trickle which goes completely dry at times. The stretch, the first major section of the fabled Rio Grande in Texas, is now commonly called the Forgotten River.

ONLY THE RIO CONCHOS CAN RESCUE the Rio Grande. This reality hasn’t sneaked up and surprised anyone. Back in 1944, to address the increasingly disappearing flow of the Rio Grande south of El Paso, the U.S. and Mexico signed the treaty for Utilization of Waters of the Colorado and Tijuana Rivers and of the Rio Grande. The pact placed the International Boundary and Water Commission (IBWC), under the direction of the State Department, in charge of overseeing all formal water agreements between the U.S. and Mexico. Under the treaty’s provisions, to ensure that the Rio Grande would always have water to provide relief for the mushrooming border towns and cities that needed drinking and irrigation water, Mexico would release one third of the water from the Río Conchos and five other Rio Grande tributaries—an annual average of 350,000 acre-feet. For this, Mexico would still own two thirds of the Conchos water. (Near Yuma, Arizona, Mexico also gets 1.5 million acre-feet from the Colorado River.) The Amistad and Falcon reservoirs would be built on the Rio Grande to store the water and check floods, and the Conchos would set the border stream flowing again.

In June, a few weeks before my trip to the Rio Grande’s mouth, I drove south from El Paso to Delicias, a pleasant town south of Chihuahua City that has long been home to the Conchos’ richest farming country. A young woman named Karen Chapman, who works for the Austin chapter of the New York-based green group Environmental Defense, came along to help with introductions and translation. “Chihuahua had three years of crippling drought in the mid-nineties,” she briefed me. “But when the weather improved in 1997 and the reservoirs began to stabilize, authorities allowed the farmers to use more water to irrigate fields and recoup losses. The treaty obligation of three hundred fifty thousand acre-feet a year is an average, measured in five-year cycles. The Mexicans thought they could make it up. Then it stopped raining again, especially in 2001.”

Dozens of Conchos tributaries snake through the Sierra Madres Occidental range of Chihuahua and Durango. Home to Tarahumara, Pima, Yaqui, and other indigenous tribes, the river’s watershed is best known for mines and vast ranches, but the upland Conchos valley has been farmed and irrigated since the seventeenth century. Yet this is parched country, and when I last traveled here, two years ago, the vistas were sand-colored and desolate. But in June, the short-grass range and sparsely wooded peaks had greened up spectacularly. The summer monsoons, fragrant afternoon showers moved east by fronts off the Pacific, came early, and the rain kept up. We passed a high-sided truck loaded so extravagantly with fresh hay that it looked like a McDonald’s carton stuffed with french fries. The streets of Delicias were full of storm water when we arrived. People looked happy walking in the rain.

The next morning, in a spare downtown office, we met Ricardo Valdez, the district chief of the Comisión Nacional de Agua (CNA), the national water commission. “In Mexico, all water belongs to the federal government,” he began, attempting to explain how Mexican water-rights laws differ from those in Texas and the U.S. Owning land in Mexico doesn’t guarantee you access to the water. With quasi-governmental authority and great political power, irrigation districts in Mexico manage landowners’ water privileges. Valdez said, “The district in Delicias has eighty thousand hectares”—about 200,000 acres—”that are irrigable, but realistically only forty or fifty percent of those qualify. We have problems with salinity, and this drought has been severe. We try to increase efficiency by lining the irrigation canals and leveling the fields, but that costs money. And water is just one element in the production chain. With free trade, we have to compete in the global market. Many hectares have been taken out of production.”

Later in the morning, employees of the CNA took us to the Madero reservoir, in the hills above Delicias. Our guide told us that the small lake had risen about 25 feet since the summer rains began. Still, he said, Madero stands at just 34 percent capacity, and other Conchos reservoirs are doing no better. Agriculture commissioner Susan Combs has been offering satellite photographs as proof that the Chihuahuans have been hoarding water and turning the countryside green all along. She says that the Chihuahuans have rushed into production crops that require great amounts of water and that they open their gates and just flood the fields, an obsolete and wasteful way to irrigate.

I know little about farming and less about interpreting satellite photographs. But I saw the Madero Lake two years ago, and the water level was far higher then than what I saw in June, even after all the rain and the 25-foot rise. And to modernize the way Delicias farmers irrigate would mean investing millions of dollars in new equipment, capital that just hasn’t been available.

Still, around Delicias I encountered sprawling pecan orchards and fields of tomatoes, chiles, onions, cotton, and one of the world’s thirstiest crops, alfalfa. Our CNA guide took us to a farm where peacocks strolled the grounds and workers were sorting garlic in a barn thick with the smell. The head of the family farm was on an errand; his daughter walked out from the office. About thirty, Rosa María Ruiz is shy but confident. She listed the crops of the three-hundred-acre farm with precision and pride. Chapman asked her if she had heard much discussion of Mexico’s water debt and the dispute with farmers in Texas. “We’re all aware of it,” Ruiz said. “But it’s too complex. Nobody is paying much attention to it.”

One of the major complexities at play is Mexican electoral politics. Only by 1929, twelve years after the Mexican Revolution ended, was order fully restored by the oligarchy of generals and plutocrats that would come to be known as the Partido Revolucionario Institucional. The PRI was rewarded with overwhelming support from the electorate for 71 years. The most durable rival to emerge was the conservative, business-oriented Partido Acción Nacional (PAN), and it gained footing as the principal opposition by winning races in Chihuahua in the seventies. In 2000 Vicente Fox, a rancher, Coca-Cola magnate, and governor in Guanajuato, expanded the PAN base and sent a thunderbolt through the nation when he was elected as the first PAN president in the nation’s history. Fox is fluent in English and has a long-standing friendship with President Bush. While trying to deliver the reforms and economic recovery he has promised his country, Fox wants to advance trade, win concessions on immigration, support the war against terrorists, and maintain cordial relations with the U.S.

But by the time the PAN won its landslide in Mexico City, the PRI had figured out how to win in Chihuahua. The state’s incumbent PRI governor, Patricio Martínez, has challenged drug lords and survived an assassin’s bullet. He has a populist streak and an oratorical flair, and the way to cultivate and flaunt support in Chihuahua, he seems to figure, is not to roll over for a bunch of Texans. Besides, why make things easy for the president of the PAN? Fox is limited to a single six-year term, and someone has to emerge as the PRI’s candidate in the next election. Why not a charismatic governor who stands up to the United States? “Neither war nor boycott nor discord is going to put one more liter of water in the valley of the Río Bravo,” Martínez said in one speech. “The sky is denying us all.”

A political ally of the governor is Rogelio Bejarno, the head of the local irrigation district. Seated behind a large desk in his Delicias office, Bejarno is a tanned and broad-shouldered man with rugged features and a movie star’s smile. He is a farmer, rancher, and former mayor of Delicias. He told us bluntly that all these questions about the Conchos had begun to bore him. “It does not bother me a bit if Texans are upset,” he said. “Our people have suffered. They’ve had to reduce planting. Here, if the land is not productive and people don’t use their irrigation rights, they lose the water. It’s reassigned. Many have given up.”

“What happens to them?” I asked.

Bejarno tilted his head and smiled. “They sell their land and go work in Texas.”

And even if the Chihuahua reservoirs are full, as Combs insists, and the area around Delicias is green and rich at the expense of U.S. farmers, the rest of the land along the Conchos varies greatly. Between Chihuahua City and the river’s mouth at Ojinaga are a hundred miles of exceedingly dry and almost empty country. Here Pancho Villa rode to fame in the Mexican Revolution, pursued by the leftist correspondent John Reed and the punitive expedition of General John J. Pershing. In a massive cordillera a few miles from the border, the Conchos flows through a chasm, Cañon del Peguis, that is as awesome as any in Big Bend. Below these mountains, the irrigation ditches resume again, but there is none of the lushness. There are no peacocks and damn few chickens. The people in this stretch of the valley are desperately poor. When you drive through this country, the surreal reality becomes all too clear: The fight is about water in the desert, a place where there really is no water to begin with. And given the seeds of resentment that were planted here more than 150 years ago, it is easy to understand why the few farmers left scratching out a living with Conchos water would want to hold on to every last drop.

REAL LIVES AND FUTURES ARE at stake in this conflict. On the Texas side of the Lower Rio Grande Valley, about 1,700 farmers rely on their irrigation rights; at an average 26.5 inches a year, the rainfall is too meager and erratic to support commercial production. Joe Aguilar farms three thousand acres of vegetables, cotton, corn, and grain at Peñitas, near Mission; he irrigates about one thousand acres. Aguilar works the land his dad cultivated. He hopes his daughter will continue to work the farm but wonders if there will be one. Aguilar is a reserve constable and a school board member. He’s no firebrand, but he is deeply alienated. Last April he and a few other growers got to meet President Bush at his Crawford ranch, and Aguilar told the president that he was going to take part in a tractor blockade of bridges over the water issue. The president wished the men his best and said he was trying to help.

The four-hour shutdown of three international bridges in May was peaceful; cops stood aside. The Texas farmers had hoped they would be met by growers in Tamaulipas who have also been left low and dry by the watermasters in Chihuahua. But the Texans’ hope for a united front in both valleys would not be rewarded. Tamaulipas farmers later blocked bridges with their own tractors, but Texas farmers claim their Mexican counterparts were protesting to keep the water, not give it to Texas.

Efforts by farmers on both sides to get their governments to move on the Conchos water fight have had little effect. Their politicians seem more inclined to dance around the subject. In early June Fox planned to visit Texas, meet with Governor Perry and President Bush, and address the Legislature. The Mexican congress, however, which was aggravated by the water conflict and U.S. rhetoric and which has purse control over presidential travel abroad, vetoed the trip. Then the IBWC signed Minute 308, an agreement with the agency’s counterpart in Mexico, the Comisión Internacional de Límites de Aguas, in which the Mexicans agreed to release 90,000 acre-feet. But the agreement was more about posturing than about taking real action; it referred to water that was already stored in the lakes of Amistad, above Del Rio, and Falcon, above Roma. The order required no more release downstream from the Conchos reservoirs, and it could be rescinded at Mexico’s request if drought on the Conchos worsened. Secretary of State Colin Powell received a letter from Texas growers calling Minute 308 a “colossal failure” and an “embarrassment to our country.”

Trying to ease the tension, the State Department sent Dennis Linskey, its director for U.S.-Mexico border affairs, to the Valley. Joe Aguilar told me that he spoke up at the July meeting: “I asked him, ‘Have we been sold to Mexico, and if we have, for how much?’ He thought I was being sarcastic.”

Later that month Carlos Ramirez, a former mayor of El Paso and the head of the U.S. section of the IBWC, was being excoriated in a Washington meeting by Texas congressmen and their aides. Exasperated, Ramirez blurted out that President Bush had called him directly and ordered him to sign Minute 308. So far, Ramirez still has his job, but the leak made it clear to Valley farmers that Bush wasn’t necessarily looking out for their livelihoods. And in August Fox canceled another planned trip to Texas. He attributed the cancellation to Texas’ execution of a Mexican national, but Aguilar and other Valley farmers were planning a public demonstration against him and the president in Crawford.

With more success than Bush and the frustrated Governor Perry, Susan Combs has positioned herself as the Valley growers’ most prominent champion. In her fifties, the Republican agriculture commissioner is a tall, attractive West Texas rancher and Vassar graduate. She is a skillful politician, and in a state dominated by Republicans, she could someday seek higher office. “If the Mexicans are not going to give us the water,” she told me, “then by God we ought to ante up and help our people in the Valley. How about the filling stations? How about the grocery stores? How about the guys who fix the trucks? How about all the collateral damage? We really could turn the Valley into a parking lot.”

Combs’s attitude toward Chihuahuan politicians is undisguised contempt: “From everything I’m hearing, their position is, ‘We’re not going to let the gringos have it.’ They’ve got a governor in Chihuahua who says, ‘If the rain falls here, it’s mine.’ He does not believe he has to be a partner in the treaty. What kind of neighbor is that? All we hear from them is ‘Gimme water. Gimme money.’ They’re like irresponsible toddlers.”

“So you stick by your statement that Chihuahua is a rogue state,” I remarked.

“Sure. Yesterday I called them “renegade.” Whatever. Starts with an r.”

On October 2 Mexico officially defaulted on a Rio Grande water debt of almost 1.5 million acre-feet. A week later, Combs released new satellite photographs from the University of Texas Center for Space Research which showed, she claimed, that a tropical storm had increased Mexico’s storage to 2.5 million acre-feet. Fox’s point man on the water dispute is Alberto Szekely, an urbane Mexico City diplomat. “Talk to the author of that study, at the Center for Space Research,” Szekely told me over the phone in response to Combs’s new pronouncements. “He will tell you those figures refer to our total storage capacity and don’t allow for silt. Our storage in the reservoirs is exactly what we say it is.”

“What is the solution to Mexico’s water debt?” I ask.

“The solution,” he answers lightly, “is that Mexico will work out a schedule of repayment over the amount of time allotted by the treaty, which is five years.”

The Mexican and U.S. presidents finally met for 45 minutes at an Asian-Pacific Economic Cooperation summit in Baja California in late October. Bush wanted Fox’s support in the U.N. Security Council vote on Iraq. Fox wanted Bush to make some concessions on immigration. Neither leader yielded on those issues and—to the amazement of Valley agriculture figures—the Rio Grande and the water debt were not prominently mentioned as items on the agenda.

“Look,” says Jo Jo White, the manager of the Valley’s Mercedes irrigation district, “We realize that with trade, immigration, drugs, terrorism, and the rest, the concerns of Rio Grande Valley farmers are a pretty small part of the equation. But we really do feel like we’ve been abandoned by our government. We’re at wits’ end. This situation with the Conchos has been going on since 1996, and the worst could be yet to come. We really could lose our citrus and sugarcane production down here.”

White is prominent in an organization called Texans for Treaty Compliance. For the past three or four years, they tossed around a plan for just scrapping the 1944 treaty. Let Mexico keep the Conchos water, their argument ran. Under the treaty, the U.S. releases about a tenth of the flow of the western Colorado, 1.5 million acre-feet a year, to Mexico. Cut them off and pipe Colorado water from Hoover Dam over the desert and Rockies, to the Rio Grande, at a pipeline construction cost of $1 million a mile. It is a desperate idea predicated on the notion that Arizona and California, who have tremendous water problems of their own, are going to give up supply to help farmers in South Texas. Drought has set in all over the West. Even Combs predicts that because of the lack of snowmelt in the southern Colorado Rockies, the U.S. will likely be facing its own water debt to Mexico.

At his farm near Mission, Joe Aguilar tells me that he believes the presidents of both countries have good intentions, but he fears their hands are tied by their allegiance to multinational produce companies. Aguilar has been selling acreage and buying trucks to start a small transport firm, trying to diversify. Like most area farmers, he’s beginning to understand that his government could dodge this issue for years, and there is no relief in sight.

Ironically, in their fight over the Rio Grande, the Texas farmer and the Chihuahua politician, Patricio Martínez, wind up sounding like each other. “If we’re ever going to get any help,” says Aguilar, “it’s going to have to come out of the sky.”

THE DAY GILBERTO RODRIGUEZ TOOK ME to Boca Chica, he said that as a boy he could remember a tiny Mexican village beside the river’s mouth. His reminiscence made me think of Paul Horgan’s masterful book, Great River: The Rio Grande in North American History, and its passages on a similar hamlet, the long-extinct Bagdad. It was a cluster of reed huts plastered with mud and oyster shells and occupied mostly by smugglers, until some hurricane swept it away. An Army lieutenant from Indiana named Lew Wallace was ordered to stand watch on Bagdad in 1846, during the U.S.-Mexico War. Later in life, as a retired general and the territorial governor of New Mexico, he would orchestrate the manhunt for Billy the Kid while writing the best-selling novel Ben-Hur. But that disease-ridden bivouac on the Gulf had the young soldier wondering if he had any future at all. In Horgan’s book, Wallace described the sight of fresh troops “marching by, flags flying, drums beating, and hurrying aboard boats as if they smelled the contagion in our camp or feared an order for them to stop and take our place. There was not a soul among us so simple as not to see that we were practically in limbo.”

The fighters of the Rio Grande’s water war are caught in their own drumbeats and limbo. They are trying to stick it out, hoping that relief will finally come, but increasingly, they’re left only with desperate plans such as piping water thousands of miles or blockading international bridges. About the time Mexico defaulted on its debt to the U.S. and the presidents chose to avoid the subject, three fed-up Mexicans dug a four-hundred-foot-long ditch with shovels through the sandbar at Boca Chica, enabling the Rio Grande to run free for the first time in nearly a year. But within a week the tides and currents just laid the sand back in strips. The bar was intact. Days later, heavy rains set in, and muddy floodwater again washed out into the surf. But as the year warms up, the flow will again grow feeble. The Rio Grande has become the river that can no longer find its way to the sea.