When I was in college, we studied California history, which did cover the areas you're looking for--especially since it's so much a part of all of California. The instructor wrote the textbook (this was in 1981, so I'm guessing the book is long out of print), but it stands to reason you might be able to find something on a California university website. On a quick search, I got this:
http://www.lib.berkeley.edu/EART/rancho.html That one's not documented with sources, but you should be able to find others. You could check UCLA and CSUN.
If your library has an online research database (mine has one that searches magazines and newspapers), also try there for local interest articles. I've found some stuff I didn't expect would be published in the newspaper, so you can never tell.
Also check on the missions, since there's a lot of California history there, and you're bound to find information leading to the specific material you're looking for.
