Okla. Stat. tit. 18 § 437.9
Notwithstanding any other provision of this act, the bylaws may provide that the territory in which a cooperative supplies electric energy to its members shall be divided into two or more voting districts and that, in respect of each such voting district, (1) a designated number of trustees shall be elected by the members residing therein, or (2) a designated number of delegates shall be elected by such members, or (3) both such trustees and delegates shall be elected by such members. In any such case the bylaws shall prescribe the manner in which such voting districts and the members thereof, and the delegates and trustees, if any, elected therefrom shall function and the powers of the delegates, which may include the power to elect trustees. No member at any voting district meeting and no delegate at any meeting shall vote by proxy or by mail.
Okla. Stat. tit. 18, § 437.9