California Code, Government Code - GOV § 66495

At the time of making the survey for the final map or parcel map unless the survey is not required pursuant to Section 66448, the engineer or surveyor shall set sufficient durable monuments to conform with the standards described in Section 8771 of the Business and Professions Code so that another engineer or surveyor may readily retrace the survey.  He shall also set such additional monuments as may be required by local ordinance.  The local agency shall require that at least one exterior boundary line of the land being subdivided be adequately monumented or referenced before the map is recorded.