Okla. Stat. tit. 62, § 62-424: Tax for payment of bonds and creation of sinking fund

The governing body, or authority of any county, city, town,

township, board of education, school district or other municipal

corporation, issuing refunding bonds under authority of this act,

shall provide, prior to the delivery of said refunding bonds, for a

levy of annual taxes on all taxable property in the county, city,

town, township, board of education, school district, or other

municipal corporations, as the case may be, sufficient in amount to

pay, and for the express purpose of paying, the interest on said

bonds as it falls due, and also to pay and discharge the principal

thereof at maturity; and, in every instance in which any county,

city, town, township, board of education, school district or other

municipal corporation shall issue bonds under this act, it shall be

the imperative duty of the proper officers, whose duty it may be to

levy taxes, to annually levy, at the time of making the levy of

other taxes, a tax sufficient in amount to pay the interest upon

said bonds and the coupons as they become due, and to create a

sinking fund for the payment of the principal of such bonds at their

maturity.