California Code, Government Code - GOV § 24051

(a) On or before July 10th in each year, or at any other interval designated by the board of supervisors, each county officer or person in charge of any office, department, service, or institution of the county, and the executive head of each special district whose affairs and funds are under the supervision and control of the board of supervisors or for which the board is ex officio the governing body shall file with the county clerk, or with the county auditor, according to the procedure prescribed by the board, an inventory under oath, showing in detail all county property in his or her possession or in his or her charge at the close of business on the preceding June 30th.

(b) By ordinance the board of supervisors may prescribe an annual or any other period, provided that the period shall not be in excess of three years, for preparation of the inventory and a correspondingly different date for its filing, and may prescribe the manner and form in which the inventory shall be compiled. The inventories shall be kept of record by the county clerk or auditor for at least five years. Any inventory which has been on file for five years or more may be destroyed on order of the board of supervisors or may be destroyed at any time after the document has been reproduced in accordance with Section 26205.1.

(c) A true copy of the inventory shall be delivered by the person who made it to his or her successor in office, who shall receipt for it. The receipt shall be filed with the county clerk or county auditor.