The description of Tumwater Canyon --- a seven-mile stretch of white water on the Wenatchee River above the town of Leavenworth --- appears to be somewhat understated.
The author of this section glosses over Tumwater's tumultuous rapids and ends the brief paragraph with, "If you want excitement, this is the section for you."
My suggestion would be, if you are an expert river runner with top-of-the-line equipment and you have a partner similarly geared and experienced AND you are unfazed by incredibly powerful waves and hydraulics, you might want the personal challenge of Tumwater Canyon at high water.
It is NOT commonly rafted by commercial rafting companies --- at least, not the stretch from the foot of Exit Drop Rapid and upstream. With the advent of Creature Craft, perhaps some rafting entrepreneur will believe it is commercially viable. Even so, I would not suggest the Tumwater Canyon section of the Wenatchee for anyone other than very experienced river runners. http://orionexp.com/
"If you want excitement, this is the section for you."
- Rafting the Wenatchee River (view on Google Sidewiki)