Here’s a list of private elementary schools in California, by county.
http://www.privateschoolreview.com/state_elementary_schools/stateid/CA
Click on the county name to see a list of private schools in that county.
Click on the name of the school to see more info about that school.
(Most are Christian, or Catholic, or Montessori.)
Also try http://www.greatschools.org/california/
Come to think of it, that goes for all private schools.