Cal. Gov. Code § 26802.5

In the Counties of El Dorado, Imperial, Kern, Kings, Lake, Marin, Merced, Modoc, Monterey, Napa, Nevada, Riverside, San Joaquin, Solano, Sonoma, and Tulare, a registrar of voters may be appointed by the board of supervisors in the same manner as other county officers are appointed. In those counties, the county clerk is not ex officio registrar of voters, and the registrar of voters shall discharge all duties vested by law in the county elections official that relate to and are a part of the election procedure.