Okla. Stat. tit. 19, § 766

When such time shall have elapsed that it is conclusively presumed that the taxes on any such property have not been paid, then the board of county commissioners shall have power and authority to order and direct that the district attorney file an action in the district court to foreclose the lien of the county on such property for the unpaid taxes thereon, and the proceedings to foreclose any such lien for the unpaid taxes shall be the same as the foreclosure of a mortgage for default in payment, and without appraisement; provided, that any number of persons may be made parties defendant in the same action.