Strange, awkward title, Even for keyword reasons. Ought to be "White Water River Rafting Rivers in the state of Washington".
The information, however, is excellent, and certainly not automated gobbledygook.
Green River Gorge
Three Doors Rapid just below the Nozzle can be a big surprise when the river is cruising above 2,500 cfs. It is highly unlikely the Green will run in 2010.
Watch for sweepers and logjams on the Cispus. Contact someone who rafts the river on a somewhat regular basis before attempting it. Or hire an outfitter.
Actually, Snohomish County is the managing agency that requires helmets, and the Wind River in the Columbia Gorge is much more challenging.
Boulder Drop Rapids, though much easier than it once was with non-self-bailing rafts, is sometimes considered to be Class V. The main reason being that rescue at Boulder Drop can be very difficult at higher water levels.
Sauk and Suiattle Rivers
I have no idea why the Sauk River gets such short shrift here because of these two rivers the Sauk River is ten times more enjoyable, even for novices. If there is Class IV on the Sauk, it is only a couple of Class IV 'moves'.
The Sauk River is also fed by glaciers and is often navigable late into the summer. Orion River Rafting rafted it one year on the 22nd of August.
All in all this is a nice compendium of the commercially rafted rivers in the state of Washington.
"Water Rafting Rivers"
- Water Rafting Rivers (view on Google Sidewiki)