California Code, Code of Civil Procedure - CCP § 488.325

To attach (1) growing crops, (2) timber to be cut, or (3) minerals or the like (including oil and gas) to be extracted or accounts receivable resulting from the sale thereof at the wellhead or minehead, the levying officer shall comply with Section 700.020 and the recorder shall index the copy of the writ of attachment and a notice of attachment as provided in that section.