Cal. Penal Code § 1550.3

The officer or persons executing the Governor’s warrant of arrest, or the agent of the demanding State to whom the prisoner has been delivered may confine the prisoner in the jail of any county or city through which he may pass. The keeper of such jail must receive and safely keep the prisoner until the officer or person having charge of him is ready to proceed on his route. Such officer or person shall be charged with the expense of keeping the prisoner. The officer or agent of a demanding State to whom a prisoner has been delivered following extradition proceedings in another State, or to whom a prisoner has been delivered after waiving extradition in such other State, and who is passing through this State with such a prisoner for the purpose of immediately returning such prisoner to the demanding State may confine the prisoner in the jail of any county or city through which he may pass. The keeper of such jail must receive and safely keep the prisoner until the officer or agent having charge of him is ready to proceed on his route. Such officer or agent shall be charged with the expense of keeping the prisoner. Such officer or agent shall produce and show to the keeper of such jail satisfactory written evidence of the fact that he is actually transporting such prisoner to the demanding State after a requisition by the executive authority thereof. Such prisoner shall not be entitled to demand a new requisition while in this State.