California Code, Probate Code - PROB § 8909

A probate referee who appraises property in an estate shall retain possession of all appraisal reports and backup data used by the referee to appraise the property for a period of three years after the appraisal is filed.  The probate referee shall, during the three-year period, offer the personal representative the reports and data used by the referee to appraise the property and deliver the reports and data to the personal representative on request.  Any reports and data not requested by the personal representative may be destroyed at the end of the three-year period without further notice.