Okla. Stat. tit. 19 § 1247
Assessments in conformity to the appraisement and apportionment, as corrected and confirmed by the board of county commissioners, shall be payable in ten equal annual installments. The assessments shall bear interest at the rate of not more than thirteen percent (13%) per annum until paid, payable in each year at such time as the installments are made payable. The board of county commissioners of said county shall levy assessments by resolution in accordance with said appraisement and apportionment, as confirmed, against the record title holders of lots and tracts of land liable for said assessments. The resolution shall provide that the record title holders of the assessed property shall have the privilege of paying the amounts of their respective assessments without interest within thirty (30) days from the date of the publication of such resolution. The special assessments and each installment of such assessments and the interest on such assessments are hereby declared to be a lien against the lots and tracts of land assessed from the date of the publication of the resolution levying the same. Said lien shall be coequal with the lien of other taxes and prior and superior to all other liens against such lots or tracts of land. The lien shall continue for unpaid installments and interest until such assessments and interest thereon shall be fully paid. Unmatured installments shall not be deemed to be within the terms of any general covenant of warranty.
Okla. Stat. tit. 19, § 1247