Okla. Stat. tit. 68 § 2941
Any and all ad valorem taxes and assessments, together with interest, penalty and costs, heretofore or hereafter levied for any year upon any real property and any lien created thereby in this state are hereby released and extinguished forever upon the expiration of seven (7) years after the date upon which any part thereof became or shall become due, and any lien for ad valorem taxes or assessments together with interest, penalty and costs, for any tax year or years which has heretofore accrued or may hereafter accrue because of the failure of any real property to have been assessed or taxed and placed upon any tax roll, shall be and are hereby extinguished upon the expiration of seven (7) years from the date when such lien would have accrued had such assessment or assessments been made or placed upon the tax rolls as required by law.
Okla. Stat. tit. 68, § 2941