Cal. Welf. & Inst. Code § 888

Any county establishing a juvenile ranch or camp under the provisions of this article may, by mutual agreement, accept children committed to that ranch or camp by the juvenile court of another county in the state. Two or more counties may, by mutual agreement, establish juvenile ranches or camps, and the rights granted and duties imposed by this article shall devolve upon those counties acting jointly. The provisions of this article shall not apply to any juvenile hall.