Okla. Stat. tit. 82 § 562
Each director before entering upon his official duties shall take and subscribe to the Constitutional oath before a suitable officer and further that he will honestly, faithfully and impartially perform the duties of his office, and that he will not be interested directly or indirectly in any contract let by said district, which said oath shall be filed in the office of the clerk of said court in the original case. Upon taking the oath, the Board of Directors shall choose one of their number President of the Board, and shall elect some suitable person Secretary of the Board, who may or may not be a member of the Board. Upon organization of the Board of Directors, and as often thereafter as may be necessary to correctly reflect all changes therein, a certificate shall be filed in the initial case, by the President of the Board, setting forth the names, addresses and official titles of all officers of the District. Such Board shall adopt a seal, and shall keep in a well-bound book a record of all its proceedings, minutes of all meetings, certificates, contracts, bonds given by employees and all corporate acts, which record and proceedings, so recorded, shall be signed by the said Board of Directors or such members of said Board, concurring in said acts or proceedings, at the time of the making of such record or on date of the first meeting of the Board thereafter, which shall be open to the inspection of the owners of property in the district, as well as to all other interested parties, said record is hereby declared to be the official record of the district, and shall be conclusive evidence as to all actions, proceedings and notices and the contents thereof affecting said district.
Okla. Stat. tit. 82, § 562