Spent a few hours in this stretch of river, some time ago. Not much success, that day, but definitely a place I plan to give another try to, this year. The American River is followed for its entire length by a two-lane highway, heading up to Mt. Rainier, from Yakima. In many areas, though, the river snakes away and gives you enough distance and a wall of trees, so the road isn’t heard.
Also great that so many of the nearby rivers wind through canyons, so you get these amazon rock faces, some times dropping straight down into the water.