Okla. Stat. tit. 19, § 19-384: Tax levy

When the question submitted involves the borrowing or

expenditure of money the proposition of the question must be

accompanied by a proposition to authorize a tax for the payment

thereof in addition to the usual taxes provided for by law; and no

vote adopting the question proposed shall be valid unless it

likewise adopts the amount of tax to be authorized to meet the

liability incurred.