Cal. Fish & Game Code § 1500.5
(a) The following rules govern an exchange or sale of property pursuant to Section 1500:
(2) If a parcel contains more than 15 acres, the director shall except and reserve to the state all mineral deposits, together with the rights to prospect for, mine, and remove the deposits.
The rights to prospect for, mine, and remove shall be limited to those areas of the property conveyed that the director, after consultation with the State Lands Commission, determines to be reasonably necessary for the removal of the resources and deposits.