Cal. Rev. & Tax. Code § 38351

Every person who owns timber subject to a timber harvest plan, every person who is required to file a notice of timber operations with the State Forester, every person who owns timber maintained for eventual harvest as Christmas trees, and every person who is the first person who acquires either legal title or beneficial title to downed timber or timber after it has been felled from land owned by a federal agency or any other person or agency or entity exempt from state taxation under the Constitution or laws of the United States or under the Constitution or laws of the State of California, shall register with the board giving such information as the board may require.