We camped at the Chamberlin Falls section Put-In for a few nights and did runs on the N.F. and S.F. American.
Up north we camped on the Salmon at the Nordheimer Campground, plenty of free camping in that area.
We also camped in various places along the way. Free camping wasn't too hard to come by.
The American rivers are SW of Lake Tahoe by 1-2 hours.
The Salmon (Smith, Trinity) are 3-5 hours NW of Sacramento.