ON DAY SEVEN, I take the oars and drop us through gentle rapids and into an eddy, where our final camp on the Yangtze is on a narrow, windy beach of black sand, backstopped with walls of tiny yellow orchids. The raft behind me is rowed by Tashi, the easygoing trainee, who misses the eddy by 200 yards. "What's the Tibetan word for anticipation?" Jim mutters.

He's in a bad mood. More and more of the tributaries we pass have small dams, connected by high-tension power lines to the karaoke bars of Lijiang. The next morning, when we run the trip's last big rapid—a frothing, 500-yard chute—we get a sphincter-tightening ride down into five big troughs. Like good Taoists, we go up with the water and come down with the water, and are spit out, shivering and elated, into the sunshine.

For Jim, the scenery is only depressing. "I really love that spot," he says sourly. "I'm not gonna love it so much when it's under 160 feet of water." This area, at the bottom of the Great Bend, is scheduled for one of the first dams. On every trip, the guides spot new evidence of gold mining, test drilling for dams, or surveying crews. Since last year a gravel road has been shoved up the valley as far as our orchid beach camp, destroying miles of mountainside.

Jim's pessimism—let's call it realism—doesn't stop him from trying. "I don't have the faintest illusion that we are going to ‘save' anything," he says. "People have been coming over with grand plans for China since the Jesuits arrived in the 16th century, and getting sent home with their tails between their legs." The TNC master plan for Yunnan may blow away in the wind, the dams may go up, but, he believes, there are many skirmishes to be won. The 13 dams for the Salween are already being held for reconsideration, and, Jim says, "even if these sections get flooded, perhaps what we get started here could be leveraged in other places, other rivers in Yunnan, Sichuan, Tibet, China."

"At the very least," he continues, "we can create however small an institutional memory of a place that was lost. Could that little bit of discomfort germinate into awareness, even motion? Could the Great Bend become China's Glen Canyon—the place no one knew in the U.S., the heartbreak that continues to profoundly affect the dialogue of conservation?"

His father had told me much the same. "The Chinese are going to build dams, no doubt about it, just as the U.S. dammed the Columbia and the Colorado," Ed Norton said. Despite that, he continued, "we shouldn't write it all off, or say it's hopeless. Look at it from the long perspective. Over the longer haul, we can accomplish something here, and it is worth doing. Is China difficult? Extremely. You bet. Is it worth it? No doubt."

Instinctively, as the final miles of water pass by, we know this. The sun is warm, the paddling easy. In the course of a long week, Dragon, Mr. Exercise, and Chen Hai have become zealous rafting converts, recalculating their ecotourism curriculum and agreeing to serve as "mother-in-law" sponsors for Jim, Jed, and Willie in an educational philanthropy called FLOW, or For the Love of Water.

When we finally start rolling up the rafts, Yeshi and Tashi form a joint venture of their own. They've heard about a rafting race over in Panzhihua, the dreadful steel city where the Yangtze crosses into Sichuan. First prize is 30,000 yuan—$4,000—and the pair borrow some MTS gear and drive down, figuring to clean up.

Panzhihua is a thicket of 1960s steel mills that shroud the twisting Yangtze in yellow and brown smoke, the whole place reeking like Mordor. It is the site of one of China's largest pollution lawsuits, with 6,000 plaintiffs suing over a pair of phosphorus leaks in 2004. Looking to clean up the city's image, if not its air, Panzhihua's mayor built a special rafting facility, a muddy ditch grandly named the Chang Jiang River Rafting Training Base, and sprinkled billboards around town showing handsome Chinese yuppies splashing down through Class II froth. It isn't exactly ecotourism, but the prize money has attracted teams of wannabe rafters from around China, a sign that the Nepal model could be getting some traction.

The course, however, is mostly flat, more of an endurance test than a challenge to the Tibetans' maneuvering skills. In the end, the ToFUs get their butts kicked by some local farm boys.

Maybe there's hope for Chinese rafting after all