In Ocober, 1996, Eric Hertz of Earth River Expeditions (www.earthriver.com) ran a first descent of the upper Shuiluo, a large tributary to the Yangzte that enters at the top of the Great Bend. As with many first descents in China, it was an epic adventure. After encountering many very challenging rapids, they entered a gorge with multiple portages and after safely escaping the gorge, wisely decided to terminate their expedition near 28 07 04N, 100 33 35E (see link to 2005 expedition on the section of the Shuiluo below their take-out).
They put-in southeast of Daocheng (28 47 45N, 100 34 46E) , gradient about 35' per mile, flow about 2000 cfs. It was a large group for a first descent - 18 in two kayaks and 5 rafts. The 70 mile expedition was documented in a National Geographic article in the November 1996 issue: Rapid Descent - First Run Down the Shuiluo River.
However, the National Geographic article doesn't do justice to the expedition. Although well inside the borders of Sichuan, the local population is largely Tibetan, and interaction with them was one of the main reasons for the expedition. The article dwells heavily on "fear of dying," and not on the incredible scenery, culture and impressive skill of the group.