California Probate Records
The earliest probate records in California were kept by the probate courts in each county. Since 1879 the superior court in each county has held the jurisdiction over probate matters. The county clerk is usually the custodian of these records.
You can obtain copies of the original probate records (such as wills and estate files) by writing to the county clerk.
Many records of Humboldt, Marin, Mendocino, Nevada, Sonoma, and Sutter counties are at the California State Archives. The Family History Library has copies of some probate records, including 33,000 wills filed in San Francisco between 1906 and 1922 on 127 microfilms.