California Code, Public Resources Code - PRC § 5131

Under such limitations and restrictions as are prescribed by law, boards of supervisors may permit nonprofit incorporated historical societies to withdraw from the county records for exhibition purposes within the county any original document filed prior to January 1, 1876, when application for withdrawal is made in writing by an authorized agent of the society.  A certified copy of the document shall be prepared at the applicant's expense, and filed in place of the original.