Okla. Stat. tit. 70 § 15-101
Whenever it shall become necessary for the board of education of any school district to raise sufficient funds for the purchase of a school site or sites, or to erect or purchase and equip a suitable school building or buildings, either or both, or for the purpose of making repairs to an existing school building or buildings, or for the purchase of school furniture and fixtures, or for making improvements to any school site or sites, either or both, it shall be lawful for such board of education to borrow money for which it is hereby authorized and empowered to issue bonds bearing a rate of interest not exceeding seven percent (7%) per annum, payable semiannually, at such place as may be shown on the face of such bonds, which bonds shall be payable serially as otherwise provided by law in not more than twenty-five (25) years from date; and the board of education is hereby authorized and empowered to sell such bonds at not less than their par value; provided, before any bonds shall be issued, the board of education shall cause an election to be held in such district as herein provided; provided, further, bonds may be voted in one issue and at the same election for any or all of the purposes hereinbefore enumerated.
Okla. Stat. tit. 70, § 15-101