Okla. Admin. Code § 585:35-3-5
The corporate authority shall furnish the Board, within twenty (20) days of receipt of a notice from the Board, an alphabetical list of names, addresses, departments and job titles of all employees within the proposed bargaining unit as described in the petition. The list of employees shall be as shown by the payroll for the period immediately preceding the date on which the petition for representation was filed with the Board. The corporate authority shall designate, by notation on the list, those persons it considers to be permanent, paid employees. Failure by the corporate authority to furnish such a list within the time allowed may be deemed to be an admission of the sufficiency of the petitioner's showing of interest.
Okla. Admin. Code § 585:35-3-5