Okla. Stat. tit. 19 § 745
The board of county commissioners of any county may sell the courthouse of the county together with the real property upon which the courthouse is located if the contract price for such sale equals or exceeds the appraised value of the courthouse and real property upon which the courthouse is located. Such appraisal shall be made by the county assessor of the applicable county. The sale authorized by this section may only be made if, as part of the contract for sale, the purchaser agrees to lease the conveyed premises to the county until the county provides new courthouse facilities, whether by purchase, construction, remodeling, lease or some combination thereof. Such new facilities shall be provided within three (3) years from the date of the conveyance of the existing courthouse to the purchaser. The new facilities may be provided in whole or in part from proceeds of the sale of the existing county courthouse, including principal and interest.
Okla. Stat. tit. 19, § 745