Cal. Pub. Util. Code § 3171
Under the terms and conditions which are prescribed in the bylaws adopted by it, an association may admit as members or issue common stock to only those persons engaged in the production of gas which is to be handled by or through the association, or that use or employ any service or facility offered by the association on, or in connection with, land which is used for the production of gas, including the lessees and tenants of land which is used for the production of gas and any lessors, including any lessors, sublessors, or landlords that received as royalty, overriding royalty or rent, all or part of the gas or the value thereof, which is produced on the leased premises, and landlords that receive as rent all or part of the gas which is produced on the leased premises.
Ca. Pub. Util. Code § 3171