California Code, Civil Code - CIV § 1469

(a) Such contiguous real property is particularly described in the lease;

(b) Such successive owners are in the lease expressed to be bound thereby for the benefit of the demised real property;

(c) Each such act relates to the use, repair, maintenance or improvement of, or payment of taxes and assessments on, such contiguous real property or some part thereof;

(d) The lease is recorded in the same manner as grants of real property, in the office of the recorder of each county in which such contiguous real property or some part thereof is situate.  Such lease shall include the description of any such contiguous land described in any unrecorded instrument, the contents of which unrecorded instrument are incorporated by reference in such recorded lease.

Where several persons are subject to the burden of any such covenant, it shall be apportioned among them pursuant to Section 1467, except that where only a portion of such contiguous real property is so affected thereby, such apportionment shall be only among the several owners of such portion.  This section shall apply to the mortgagee, trustee or beneficiary of a mortgage or deed of trust upon such contiguous real property or any part thereof while but only while he, in such capacity, is in possession thereof.