Cal. Public Resources Code § 7923

Any person, legally qualified to purchase from the State public lands of the same character as the land involved in the action, may, after such order of reference has been made, present to the commission his application, in due form as required by law, to purchase the land, or any part thereof not less than the smallest legal subdivision. Upon presenting to the court in which the action is pending, a certificate of the commission, showing that such application has been so presented, and a certified copy of such application, the court may, at any time before the trial, upon such terms as may be just, allow such party to intervene in the action and contest the right of any other party thereto to purchase the land applied for by the intervenor, and to have his own right determined.