California Code, Education Code - EDC § 1253.5

(a) If a unified school district, described in subdivision (c), is subject to Section 1253, the county board of supervisors of each county wherein the district is situated may by agreement and pursuant to an appropriate resolution adopted by each board, permit the voters of the district who lie outside the county housing the county superintendent of schools who has jurisdiction of the district the right to participate in the election of such county superintendent of schools.

(b) The county elections official of each county affected by the agreement described in subdivision (a) shall be responsible for the conduct of the election within his or her county.

(c) The provisions of this section shall apply only to a unified school district which was formed on July 1, 1965, and that, as of the 1979-80 school year, maintained an enrollment of between 12,000 and 15,000 pupils.