Okla. Stat. tit. 25 § 93.2
In memory of the April 19, 1995, bombing of the Alfred P. Murrah Federal Building in Oklahoma City which killed or injured hundreds of residents of this and other states, flags commemorating this incident and the courage and compassion of the people of this state, this country and the world who have been involved in the rescue of and aid to these residents are encouraged to be flown on flagpoles throughout this state the week of each year in which April 19th falls beginning on the Sunday of such week through to the following Saturday.
The Governor may select which commemorative flag may be flown on state property each year, and citizens and the governing body of each political subdivision of the state may select the commemorative flag of choice for their own respective property.
Okla. Stat. tit. 25, § 93.2