California Code, Health and Safety Code - HSC § 121400

If the place of confinement of a person confined under the provisions of Section 120280 is in a county other than the county where he or she was convicted, upon release he or she shall be released in the custody of the sheriff of the county where he or she was convicted, and the sheriff shall forthwith return him or her to the place where he or she was convicted without the necessity of a court order or other process. The sheriff shall prior to the return of the person notify the health officer having jurisdiction of the area to which he or she will be returned of the date he or she will reach that area.