LOOKING DOWN on the river provides a different perspective from being on it. In the days before the rafting trip, I made a three-day traverse of the high trail through Tiger Leaping Gorge with an American friend, Bret Sparling. After seven years in China, often earning his living as a drummer in cover bands, Bret spoke flawless Mandarin and even understood the mystifying reversed tones of the Yunnan dialect. Walking beside him opened a door to the only people never consulted about dams: the peasants they displace.

Dressed in a white Tibetan cowboy hat and carrying little more than a copy of the Tao Te Ching, Bret was an indefatigable hiker. The trail carried us thousands of feet above the Yangtze, its roar reduced to a background whisper. Hawks rode the thermals below eye level; across the river, the walls of rock mocked our eyesight, stretching from the Yangtze itself to the top of 18,359-foot Jade Dragon Snow Mountain, often lost in clouds.

Despite the impossible terrain, we found tiny villages hidden in the folds of the hills, where farmers worked terraced rows of wheat and black pigs rooted in slop buckets. Dotted along the trail were more hamlets, each with a simple guesthouse used by the dozen foreign trekkers we met each day. (Dragon would later tell me that the high trail, with its local tourism infrastructure, was China's single best model of sustainable ecotourism.) The first hostel was run by a tough little Yunnanese man married to an Australian woman who ran her own guesthouse down the trail. As Bret worked on a translation of the Tao, with its injunctions to bend to the flow of water, the proprietor filled my ear in his strong Down Under English with tales of "Beijing police" who threatened local people for protesting the dam. These national police—plainclothes officers of the Public Security Bureau, he suggested—had walked through the gorge just a few days earlier, forcing everyone with a computer to register it. Local police routinely intimidate the few dam critics. Yu Xiaogang, the founder of the Yunnan-based NGO Green Watershed, was briefly detained while canvassing locals about the dams in Tiger Leaping Gorge. When another activist died of a heart attack, lying next to his wife, our host saw the death as a Beijing plot.

"You must know China," the man said in a stage whisper late that night. "China has a way to make you dead. China can give you a car crash, or send a robber to your house."

Hiking out at dawn the next morning, we found a sign in the middle of the trail:

STRICTLY FORBIDDEN TO GRAZE ANIMALS, CUT WOOD, CLEAR FIELDS, START FIRES

Beneath that it read, in bold:

AGAIN STRICTLY FORBIDDEN TO GRAZE ANIMALS

Beneath that was a man grazing 60 goats. He made us guess his age first (60), and then admitted that he paid no attention to the government's sign, which had been there for only five months. He shared the news that matters to farmers—plums were up, peppers down—and pointed to his forbidden animals. The goats belonged to his daughter, and were literally her college tuition. It was a routine Chinese trade-off—trashing your local environment to climb one step out of poverty.

When he heard I was rafting the Yangtze, he asked why. "That's not exciting," he said, peering at the whitewater thousands of feet below. "That's crazy."

The trek expired 18 miles later in Qiaotou, a dusty township of truck stops and seedy bars, where Yi women in enormous black hats prowled the market for bargains. The innkeeper's wife lived here, a tall and feverish yin to her husband's small, paranoid yang. She sold me a lunch of pork and rice, with a side of condemnation for the "cynical, conniving, and corrupt" Chinese government. If Qiaotou were flooded, the nearby areas wouldn't necessarily benefit: Electricity is usually shunted off to big cities, leaving many places poorer than before, according to a 2006 study by the Central Party School, the Communist Party's own think tank. And I already knew that the main company behind the dams, Huaneng Power, was run by Li Xiaopeng, a son of former premier Li Peng, the "butcher of Tiananmen Square," a man with enormous guanxi.

"The only thing that can stop [the dam] is big guns from outside China," she told me. UNESCO wasn't enough; global green groups had to raise a stink. So far, that hasn't happened: Unlike those threatened on Chile's Futaleufú, the Yangtze dams are virtually unknown to foreigners.

The scale of China's dam fever, and the hidden arrangements of deal making, came into focus that afternoon at a scenic overlook by the river. A caravan of five black SUVs pulled in, escorted by policemen. Eighteen men in ChiCom mufti (dark suits, cell-phone holsters, knit sweaters) dismounted and unfolded a large map. Although I couldn't read the characters, it was easy enough to read the topography: It was a map of the reservoir that will be created by the dam just above Tiger Leaping Gorge, flooding twenty-odd miles of river, displacing 100,000 people, and burying the best fields in the region. These were the engineers and subcontractors who would be profiting first, and most, from the dams's construction.

There was a fun moment when I stepped forward and, through a translator, insisted that they identifythemselves and answer questions about the dam. It was a rout: The engineers rolled up their map so fast they ruined it, and then ran for their cars, screaming, "No. No! NO!" amid blaring sirens, their SUVs peeled out of the parking lot so fast they kicked up gravel.