California Code, Government Code - GOV § 24009

(a) Except as provided in subdivision (b), the county officers to be elected by the people are the treasurer, county clerk, auditor, sheriff, tax collector, district attorney, recorder, assessor, public administrator, and coroner.

(b) Except for those officers named in subdivision (b) of Section 1 of Article XI of the California Constitution, any county office that is required to be elective may become an appointive office pursuant to this subdivision.  In order to change an office from elective to appointive, a proposal shall be presented to the voters of the county and approved by a majority of the votes cast on the proposition.  A proposal shall be submitted to the voters by the county board of supervisors or it may be submitted to the voters pursuant to the qualification of an initiative petition as provided in Chapter 2 (commencing with Section 9100) of Division 9 of the Elections Code.  Any county office changed from elective to appointive in accordance with this subdivision may be changed back from appointive to elective in the same manner.