Okla. Stat. tit. 19 § 1250
The assessments provided for and levied pursuant to the provisions of Sections 1230 through 1262 of this title shall be payable as the installments become due, together with the interest on said installments, to the county clerk who shall give proper receipts for such payments and credit the same upon the road assessment record. It shall be the duty of the county clerk to keep an accurate account of all such collections made by the clerk and to pay to the county treasurer daily the amounts of such assessments collected by the clerk. The amounts so collected and paid to the county treasurer shall constitute a separate, special fund to be used and applied to the payment of such bonds and the interest thereon, as provided by Sections 1257 through 1260 of this title. It shall be the duty of the county clerk, not less than thirty (30) days and not more than forty (40) days before the maturity of any installment of such assessments, to publish in two successive issues of a daily newspaper or in one issue of a weekly newspaper, published in the county and of general circulation in said county, a notice advising the record title holder of the land affected by such assessment of the date when such installment and interest will be due, and designating the road, street, streets, or public places, or parts thereof, for the improvement of which such assessments have been levied, and that unless such assessments shall be promptly paid, said installment and interest shall bear interest at the rate of fifteen percent (15%) per annum until paid, and proceedings taken according to law to collect said installment and interest. It shall also be the duty of the county clerk, not less than thirty (30) days before the maturity of any installment of such assessments, to send a notice by mail advising the record titleholder of the land affected by such assessment of the date when such installment and interest will be due, and designating the road, street, streets, or public places, or parts thereof, for the improvement of which such assessments have been levied, and that unless such assessments shall be promptly paid, said installment and interest shall bear interest at the rate of fifteen percent (15%) per annum until paid, and proceedings taken according to law to collect said installment and interest. Failure of the owner to receive any notice shall not invalidate any of the proceedings authorized in this title and shall not invalidate any installment or interest that may be due. It shall be the duty of the county clerk, promptly after the date of maturity of any such installment and interest and on or before the fifteenth day of September in each year, to certify such installment and interest due to the county treasurer of the county in which the improvement district is located, which installment and interest shall be placed by said county treasurer upon the November delinquent tax list of the same year prepared by the treasurer of said county and collected as other delinquent taxes are collected. It shall be the duty of the county treasurer to collect such installments of assessment, together with interest and penalty, so certified to the treasurer by the county clerk, as provided for in this section, but any taxpayer shall have the right to pay his ad valorem taxes to the county treasurer regardless of the delinquency of such assessments. Within thirty (30) days from the receipt of such delinquent assessments, interest and penalty collected by the county treasurer shall be disbursed in accordance with the provisions of Sections 1230 through 1262 of this title. Failure of the county clerk to publish notice of the maturing of any installment and interest shall in no way affect the validity of the proceedings to collect such installment and interest pursuant to the provisions of this section. All payments to the county treasurer on account of such assessments shall be certified by the treasurer to the county clerk to be credited on the road assessment record.
Okla. Stat. tit. 19, § 1250