The boards of supervisors of two or more counties may by regularly adopted resolutions or ordinances duly entered on the minutes or proceedings of their respective boards, unite in the organization, establishment, equipment, and maintenance of adjustment schools for the respective counties. In that event, the schools shall be located in one or more of the counties as shall be mutually agreed upon and designated in the resolutions or ordinances.
Ca. Welf. and Inst. Code § 963