Okla. Stat. tit. 74, § 110.6

State real estate contracts - Contingencies allowed - Restrictions. The state may enter into a real estate contract for the sale, conveyance, or exchange of real property, option to purchase real property, or a lease with an option to purchase real property that includes a contingency, not to exceed one hundred eighty (180) days, for the purposes of securing required permits, lot changes, zoning changes, and any other land use approvals necessary to use and operate the real property.