Okla. Stat. tit. 69, § 69-1719: Refunding bonds

(a) The Authority is hereby authorized to provide by resolution

for the issuance of turnpike revenue refunding bonds of the

Authority for the purpose of refunding any bonds then outstanding

which shall have been issued under the provisions of this article

including the payment of any redemption premium thereon and any

interest accrued or to accrue to the date of redemption of such

bonds, and, if the Authority shall so determine, for the additional

purpose of constructing improvements, extensions, or enlargements of

the turnpike project or projects in connection with which the bonds

to be refunded shall have been issued. The Authority is further

authorized to provide for the issuance of its turnpike revenue bonds

for the combined purpose of (a) refunding any bonds then outstanding

which shall have been issued under the provisions of this article,

including the payment of any redemption premium thereon and any

interest accrued, or to accrue to the date of redemption of such

bonds, and (b) paying all or any part of the cost of any additional

turnpike project or projects as authorized by this article. The

issuance of such bonds, the maturities and other details thereof,

the rights of the holders thereof, and the rights, duties, and

obligations of the Authority in respect of the same, shall be

governed by the provisions of this article insofar as the same may

be applicable.

(b) Bonds may be issued by the Authority under the provisions

of this section at any time prior to the maturity or maturities or

the date selected for the redemption of the bonds being refunded

thereby. Pending the application of the proceeds of such refunding

bonds, with any other available funds, to the payment of the

principal, accrued interest, and any redemption premium of the bonds

being refunded, and if so provided or permitted in the resolution

authorizing the issuance of such refunding bonds or in the trust

agreement securing the same, to the payment of any interest on such

refunding bonds, and any expenses in connection with such refunding,

such proceeds may be invested in direct obligations of, or

obligations the principal of and the interest on which are

unconditionally guaranteed by, the United States of America which

shall mature or which shall be subject to redemption by the holder

thereof at the option of such holder, not later than the respective

dates when the proceeds, together with the interest accruing

thereon, will be required for the purposes intended, or, in lieu of

such investments, all or any part of such proceeds may be placed in

interest bearing time deposits or other similar arrangements may be

made with regard thereto which will assure that such proceeds,

together with the interest accruing thereon, will be available when

required for the purposes intended.