Beggars and fruit sellers ply the ramp up from the river. Peasant women sweep the streets with crude brooms. The carcass of a dog is carried by two-wheeled cart to a farmers' market, where hungry shoppers buy everything from live ducks and bullfrogs to mandarin oranges grown on the Yangtze's lushly terraced hillside farms.

As peddlers crowd around you hawking booklets on the city's lone attraction, the Emperor of Hell Temple, a bizarre hilltop shrine that houses satanic statuary engaging in gruesome forms of torture, you glance up and spy a sign 25 feet above the sidewalk on the wall of a building. It says 135M. No further explanation is needed for the people of Fengdu. The sign shows where the Yangtze waterline will be as of 2003, when the first stage of the controversial Three Gorges Dam is completed, Asia's longest river rises 135 meters, and this city of 65,000 disappears underwater forever.

Fengdu is not alone in its fate. Three Gorges will be the largest dam in history—two football fields high, 1.3 miles across, 440 feet thick at its base—and when it is finished in 2009, it will create a reservoir 400 miles long, swallowing up more than 1,400 cities, towns, and villages and displacing 1.3 million people. Not since the Great Wall has China attempted so massive a project, and, in terms of engineering and politics, stringing that 2,500-mile defensive curtain across China's north must surely have been easier.

Fengdu's Emperor of Hell Temple.

The Yangtze is a dragon of a river—serpentine, deadly, reluctant to be tamed. At 3,964 miles, it is the world's third longest river (just behind the Nile and the Amazon), and its basin is home to one-twelfth of the planet's human population.

Flowing east from the mountains of Tibet, it gains speed from a 16,000-foot vertical drop, gathers heft from 700 tributaries, and cuts across all of China, dividing the wheat-eating north from the rice-eating south.

The Chinese government says it must build the dam to control the Yangtze's notorious flooding, produce clean hydroelectric power, develop the impoverished interior, and redirect water to the parched north. But legions of critics inside and outside China call the dam oversized and potentially disastrous.

"The Three Gorges Dam is the most socially and ecologically destructive infrastructure project in the world," says Michelle Chan-Fishel, international policy analyst for Friends of the Earth, a Washington, D.C.-based environmental group.

The dam will forever alter China's equivalent of the Grand Canyon, the limestone-walled Three Gorges, which have inspired centuries of literature and art. The fickle Yangtze used to turn especially treacherous as it passed through the narrow gorges ("like a thousand seas poured into one cup," wrote one Song dynasty poet); now that 125-mile stretch of water will, in effect, become part of a lake. It will be scenic—but much less spectacular.

The dam will also submerge roughly one thousand archaeological sites, including graves, millennium-old cliff engravings, and remnants of the ancient—but only recently discovered—Ba people (wooden Ba coffins still hang from cliffs hundreds of feet above the water in the Lesser Gorges, spectacular side canyons off the Three Gorges). Efforts are under way to move as many buildings and relics as possible, but because of a lack of time and money, less than 10 percent are likely to be saved.

Although pollution and overfishing have already wiped out much of the Yangtze's aquatic life, the dam could take a serious toll on the creatures that are left. It may imperil the nearly extinct baiji, a white fresh-water dolphin once revered in China as the goddess of the Yangtze. Among other species that could be affected are the endangered 12-foot-long Yangtze sturgeon, the Yangtze alligator, and a 3-foot variety of salamander that lives in side streams off the river. Unless China makes good on its pledge to stop dumping billions of gallons of sewage into the Yangtze every year, the dam could create a giant cesspool that breeds disease-carrying mosquitoes and malignant parasites.

Even more frightening, despite engineers' claims that the dam will be earthquake proof, is the prospect that the weight of the concrete and water could cause a shift along a fault line that runs near the dam. Add in a few other worries—China's lax construction standards, the social upheaval caused by relocating 1.3 million people, corruption scandals in which local officials were caught skimming money earmarked for those being relocated—and it is no surprise that both the World Bank and the U.S. Export-Import Bank have refused to fund the Three Gorges project, whose eventual cost has been estimated to be as high as $75 billion.

Yet the dam project offers a fascinating portrait of China in transition, of a tightly controlled nation trying to rush headlong into the freewheeling global economy but unprepared for all the consequences—one of which may yet turn out to be democracy. "To get rich is glorious," then vice premier Deng Xiaoping declared two decades ago, and the Chinese have embraced economic development as their top priority. Hence the dam, the controversy, and the need to see the Yangtze myself.

The smell of industry was overpowering when my wife, Pamelia, and I arrived 1,500 miles inland at the gargantuan commercial city of Chongqing (pronounced chong-ching, like the sound of a cash register) to begin our four-day Yangtze cruise. Spend an afternoon choking on the acrid smog of Chongqing and you appreciate why China needs to stop deriving 75 percent of its energy from coal. You also come to understand why nine of the 10 cities in the world with the worst air pollution are Chinese.

"I want to get a Ferrari, but I'll probably only be able to buy the wheels," joked Norman, our twentysomething Chinese guide, as we discussed his future and drove to the highest point in the mountainside city. Once there, we took in three memorable sights: a view (barely, through smog and fog) of two great brown rivers, the Yangtze and the Jialing, conjoining at the foot of the city; a flower display celebrating Beijing's bid to host the 2008 Olympics (chong-ching!); and a lovely 100-yard-long Yangtze mural showing the route of our cruise, from Chongqing to Yichang, location of the dam.

A boat seemingly on the verge of morphing into a river dragon has taken the concept of figurehead to the next level.

The mural showed a dotted line where the water level would be in 2009 and listed how many people would have to be relocated. "A lot of young people are happy to move," Norman said. "The new cities are nicer and there are chances for better jobs. Older people are more attached to the homes where their families have lived."

By nightfall, when part of Chongqing was lit by candlelight because of a power outage, we were aboard the Victoria Pearl, a pleasant Western river cruiser. As we set sail the following morning, we wondered how dramatically the dam was going to change Chongqing.

The city will sit at the upper end of the 400-mile reservoir, with a deep new harbor navigable by ocean freighters—theoretically. The Yangtze is China's Silt Road, carrying 500 million tons downstream each year. Many experts believe that the silt will clog Chongqing's harbor, as well as the rest of the reservoir. This is no small matter. Heavy buildups of silt could hinder the dam's turbines (which will produce 18,200 megawatts of electricity annually—as much as nine Hoover Dams—equivalent to what 50 million tons of coal could generate) and reduce its effectiveness in flood control.

These are issues Sun Yatsen, the father of the Chinese republic, didn't ponder when he first proposed the dam in 1919. They are issues Mao Zedong didn't consider in the late 1950s and '60s, when he backed the concept of a dam and took occasional swims in the Yangtze to prove that he could single-handedly conquer the formidable river.

I imagined swimming alongside Mao in the murky water. He floated more than swam, his round belly often sticking up as the swift current carried him as far as 15 miles in the span of two hours. After a Yangtze dip he wrote a poem called "Swimming" in which he envisioned the Three Gorges Dam: "Over tall chasms will be a calm lake / and if the goddess of these mountains is not dead / she will marvel at the changed world." Through four days of clouds, fog, and rain, Pamelia and I marveled at a world that is about to change. We drifted past doomed factories (900 will be submerged) and pagodas (some will be moved to higher ground). We saw bright new cities, including new Fengdu, sprouting on hilltops and watched laborers carry rich riverbed soil—baskets full of it, on both ends of straining bamboo poles draped across their shoulders—to dump trucks so it could be moved to cropland being created for the displaced farmers.

Fog and mist only deepened the beauty of the Three Gorges, which we passed through over the course of two days. Each gorge is a unique work of art, distinctive in shape, scale, and mood.

Qutang, the westernmost, is just five miles long and 300 feet across. Carved into its mottled walls are "tracker" paths used for centuries by men who pulled boats upstream against the otherwise impenetrable current. Wu Gorge (28 miles long) is famously tortuous and passes by the cloud-enshrouded 12 peaks of the mystical Wushan Mountains. Rising even higher, to 4,000 feet, are the peaks along the final gorge, Xiling (41 miles), which is pockmarked with 170 caves. Xiling was once known for its deadly shoals and barely submerged rocks. But many of those were blasted out decades ago for navigational safety. In the future, this storied chasm may become better known as the home of the Three Gorges Dam.

As we passed through this last gorge, four eagles—virtually the only wildlife we saw—circled high above a slender waterfall. One virtue of the project is that it has helped to inspire a small grassroots environmental movement. Even the Chinese government has been forced to admit that smarter ecological policies, not just a new dam, can reduce the risk of flooding along the Yangtze; authorities have acknowledged that deforestation and the draining of wetlands along the river contributed to the floods that killed 3,600 people in 1998.

"Unfortunately, China's leaders insist on following the Maoist principle of putting politics in command, in an effort to show the rest of the world that the Chinese people can accomplish anything," journalist Dai Qing wrote in 1999. Dai Qing, a voice of the green movement who was jailed for 10 months in 1989 and '90 for publishing a collection of essays critical of the dam, also charged that "by blindly giving priority to economic development, the are following the naive belief that man can simply triumph over nature even while making endless demands on it."

We reached Yiching, near the end of Xiling Gorge, and saw firsthand China's effort to triumph over the river. The world's biggest dam is currently the world's biggest construction site, with 100-foot cranes, monstrous concrete forms, and an L.A. freeway system of conveyor belts carrying crushed rock. The largest set of locks on earth is being carved through granite cliffs by 30,000 workers who have been toiling around the clock since construction began in 1994. Enough rock has been blasted out to build 100 Empire State Buildings.

Whether the dam becomes a landmark for the ages or a monument to man's rapaciousness remains to be seen. When the project was approved in 1992 by the National People's Congress, one-third of the delegates abstained or voted against it, an unprecedented show of dissent. Reports of rural protests have surfaced; some of those who are being displaced claim they are being given insufficient compensation. Chinese scientists have asked that the dam's water level be raised more slowly than originally planned, so siltation and other effects can be studied.

Even China's premier, Zhu Rongji, has been critical at times. He has ripped local officials for squandering relocation funds and has expressed concern about shoddy building practices. After a steel bridge collapsed in Chongqing in 1999, killing 40 people, Zhu warned those constructing the dam that "the responsibility on your shoulders is heavier than a mountain. Carelessness or negligence will bring disaster to future generations and cause irretrievable losses."

There will be losses regardless. Dammed, the Long River (Chang Jiang, as the Chinese call it) will swallow a valley's worth of the country's past. Grab a ride down the great Silt Road before 2003, if you can. Perhaps you can make out China's future through the mist.

If you're going ...
AAA Travel offers departures to Beijing and the Yangtze River with General Tours in May, August, September and October. These cruise tours include a five-night stay in Beijing with a full-day city tour, a full-day tour to the Great Wall and Ming Tombs, and a half-day hutong tour of Beijing by rickshaw, plus a four-night Yangtze River cruise through the Three Gorges and a night in Shanghai. Visit your nearest AAA Travel Agency or telephone (800) 922-8228 for more information.