A lease of land for the purpose of effecting the production of minerals, oil, gas, or other hydrocarbon substances from other lands may be made for a period certain or determinable by any future event prescribed by the parties but no such lease shall be enforceable after 99 years from the commencement of the term thereof.
Section 718f
Civ. Code § 718f — under California Civ. Code.
Civ. Code § 718f