look for what might be old tailing piles- the old timers got a lot of gold- but their methods were really not very good, and they lost a lot of gold out of their cruder sluices- Inside bends in rivers are good places too- as are tree roots near a river=- large boulders are good hiding spots for gold too- usually on the downstream side-
You can join GPAA and get a book of all their gold claims too, and can stay for free once you are a member-
https://www.goldprospectors.org/
They have a ton of proven places to sluice or pan- I believe they have claims on the Yuba too-
Thanks... good information.