Okla. Stat. tit. 12 § 1482
The title by which the successful claimant succeeds against the occupying claimant, in all cases of lands sold for taxes, by virtue of any of the laws of this state, shall be considered an adverse and better title, under the provisions of this article, whether it be the title under which the taxes were due, and for which said land was sold, or any other title or claim whatever; and the occupying claimant holding possession of land sold for taxes, as aforesaid, having the deed of a collector of taxes or county clerk for such sale for taxes, or a certificate of sale of said land from a collector of taxes or a county treasurer, or shall claim under the person or persons who hold such deed or certificate, or any other title or claim whatever, shall be considered as having sufficient title to said land to demand the value of improvements under the provisions of this article.
Okla. Stat. tit. 12, § 1482