California Code, Public Resources Code - PRC § 6509

If a lease is terminated by reason of the sale of the land, or by the designation of land as a base for indemnity selections, the lessee shall surrender the lease to the commission and receive in exchange therefor from the commission a certificate showing the proportionate amount of the annual payment to be refunded to the lessee, for the tract of land that has been disposed of by the State.  If the lease has been amended because of the sale of a portion of the lands described therein, the commission shall, at the option of the lessee, credit the lessee with the amount of the prepaid rental applicable to rental due for the remaining term of the lease or issue a certificate to the lessee showing the proportionate amount of the rental to be refunded to the lessee.  The State Controller, upon the surrender to him of the certificate, shall issue to the lessee a warrant for the amount payable out of the State School Fund or, if the rentals received under the lease were deposited in the General Fund, then the warrant shall be payable out of any appropriation available for such purpose, and the State Treasurer shall pay the same.