One of my favorite runs in California, with amazing scenary, fun rapids, and generally cold, clear waters. When I lived up North I used to run laps on this regularly, and it is perhaps still the stretch of whitewater I’ve paddled most.
A write up from my friend Daniel. http://www.awetstate.com/NAmericanC.html
and from AW https://www.americanwhitewater.org/content/River/view/river-detail/139/main
I will say, I think people sometimes downplay this run. I think it’s a IV and you should have decent skills and a solid roll before attempting. I think a lot of Northern California boaters have done it so much that they become a little used to it, and downplay the difficulty and difficulty of getting someone out if something does go badly. I’ve seen a number of class III kayakers have rough days on this run.