California Code, Penal Code - PEN § 4006.5

(a) Notwithstanding any other provision of law, a county board of supervisors or city council may enter into a contract with the federal government, or any department or agency thereof, to manage, control, and operate a federal prison located within the boundaries of that county or city.

(b) If a city or county enters into a contract pursuant to subdivision (a), the sheriff or chief of police, as appropriate, shall have sole and exclusive authority to keep the prison and the prisoners in it.

(c) If a city or county enters into a contract pursuant to subdivision (a), the employees working in the prison shall be employees of, and under the authority of, the sheriff or chief of police, as appropriate.