Okla. Stat. tit. 19, § 155.5v2

A. As to the records that are not destroyed as provided for in Section 155.2 of this title, the county treasurer in each county in Oklahoma, after compliance with provisions of statute as to reproduction and storage of records and providing for convenient viewing thereof, is hereby authorized, each year, to destroy the following types of work books, reports and records that have been on file or stored in his or her office for a period of time longer than the period specifically indicated, as follows: REQUISITE TIME OF TYPE OF RECORD RETAINING ORIGINAL Tax Rolls and Tax Roll adjustments 6 years Tax Sale and Resale Records 6 years Special Assessment Rolls 6 years after due date Tax Protest Records Until final settlement Tax Receipts real property, personal property 7 years Special Assessments, emergency or back assessments, and mortgage tax receipts 2 years Municipal Bond Records 7 years after final settlement Personal Tax, Warrants and Records 2 years B. All the records above described in Section 155.2 of this title, may be destroyed after two (2) years provided the same are reproduced and stored as required by law; and further provided that the State Auditor and Inspector has audited said records and has not directed such original records to be retained. Such copied records must be retained until such time as the original, if it had been retained, would have been seven (7) years old.