What a fascinating theme for a roadtrip!
Welcome to the Roadtrip America forum.
We actually don't plan custom roadtrips for people here. We are all just volunteers who enjoy roadtrips and helping people plan their trips. We do, however, help answer specific questions and provide general roadtrip advice. We just don't get into the detail you're requesting.
I would be willing to answer some questions about Native Americans in Washington state. However, that is not where you're interest lies. I'm sorry I don't know much about the Native Americans of California. Maybe someone else will pop in who can help with that.
This website has a lot of good information about Native Americans. Maybe this will help get you started in the right direction.
I think we can help you best with things like route-planning and, possibly, tips on lodging, budgeting, etc. once you figure out just where you need to go to find what you're seeking. Hope this has helped a bit.
Glad Larrison came along!
If you have further questions about routes, lodging, other things to see/do, please let us know.