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 or her 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 or her 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 reproduction of records and storage of reproductions thereof. Such reproduction and storage of records shall be done using any generally accepted current technology which will ensure safe documentation and accessibility of public records. The State Library may be given any record which would be destroyed upon request therefor.
Okla. Stat. tit. 19, § 155.1