Jan Warren (left) and Chu Siming, a key member of the bilateral rafting team in 1986 met again in Beijing. [Photo provided by Jan Warren to China Daily]

Chu says that instead of comparing the expedition to an adventure gone wrong, people should see it as a test of human resolve.

"I found rafting to be more about what it means to be human than an adventure. In an extremely dangerous and unfamiliar situation, even a little problem can be amplified into a big one."

The problem the joint team faced was not only the difficulty of the route, but also shortages of food, he says.

However, after Ken Warren and others finally acknowledged nature as the winner in their intrepid tussle, more battles lay in store when they returned to the US. The Warrens faced no less than six lawsuits from some of the American team members, including one for wrongful death.

In June 1990 the couple were vindicated in all the lawsuits, but Jan Warren says they were left more than $180,000 out of pocket because of legal fees. Ken Warren died early the next year.

"I simply couldn't handle all the loss," Jan Warren says. "I was angry and I had to spend a lot of effort to heal the mind and support my then 13-year-old son."

At one stage she refused to even talk about the expedition but says she eventually felt compelled to write about it on behalf of her late husband, who was posthumously recognized with a lifetime achievement award in Beijing, she says.

"I just cried when I saw the trophy. It is beautiful."

That is why she decided to tell the story of the Sino-US expedition in a book she self-published in the US, 1986 Sino-USA Upper Yangtze River Expedition, for which she has sought a publisher for a Chinese version.

Chu was among the attendees at the party in Beijing on Oct 29, with Zhang Jiyue, another member of the expedition, two Chinese reporters who were attached to the joint teams, and Jan Warren.

There was "lots of laughter, talking and reliving", Jan says. "I spent the day with Chu and we had a wonderful talk about the expedition."

Chu, who is now in the real estate investment and art business, gave up rafting many years ago, but Jan Warren is as keen on it as ever and holds onto the dream of promoting rafting as a sport in China.

"One of the things I still want to do even if I am too old is to organize Chinese tourists to river raft in the US. Lots of Chinese tourists come to the US these days, and we want to show them the excitement but in a careful way."

Chu reckons that as a result of the ill-fated expedition young people may have been deterred from the sport, because to this day the feat that those intrepid rafters attempted 30 years ago is a mission that remains unaccomplished.