Okla. Stat. tit. 2, § 131.9
In addition to the powers herein conferred, such board of directors shall have the power and authority to provide for during said agricultural and industrial exposition and fair or at any other time, exhibitions and contests of speed, athletic skill and other events of public and civic interest and benefit, and award suitable prizes and purses therefor, and collect reasonable admission thereto and rental fees therefrom by such activities.
Laws 1947, SB 104, p. 5, § 9.