Each utility having gas in underground storage shall report to the Commission on or before the 60th day following the last day of each month the amount and purchased cost of gas in storage as of the last day of the preceding month as set forth in OAC 165:50-3-2(a)(2)(D). The report shall be made as prescribed by the Director of the Public Utility Division.
Okla. Admin. Code § 165:45-9-7