Okla. Stat. tit. 19 § 155.1
The county assessor in any county is authorized to destroy any of the records which have been on file in his office for more than seven (7) years, including all assessment rolls, assessment listing sheets relating to tangible or intangible personal properties, monies and credits, real estate, or corporation properties, all balance sheets, and all homestead exemption applications. All records which have been on file in his office for more than two (2) years, prior to the current calendar year and less than seven (7) years, may be destroyed if compliance is made with statutes authorizing the digitizing or other reproduction of records and storage of reproductions thereof. A computer shall be provided, the costs, maintenance and supplies therefor be paid from the county general fund, to accommodate public reference to the digitized records. The State Library may be given any record which would be destroyed upon request therefor.
Okla. Stat. tit. 19, § 155.1