Okla. Stat. tit. 62 § 545
It is hereby declared to be the intent of the Legislature that this act shall apply to any and all investments that may be made from and after the effective date of this act out of the sinking funds of the state or any of its municipal subdivision, and likewise to the sale of all bonds and securities now owned or held or that may hereafter be owned or held as investments for any of the sinking funds in the custody of the Treasurer of the State, or any county, city, town or board of education thereof. It is further declared to be the intent of the Legislature that all reference in this act to sinking funds in the custody of the county treasurer shall be deemed to include the sinking funds of such county, of the several townships, and of the several dependent school districts thereof; and with reference to such county treasurer, the board of county commissioners of such county shall be deemed his governing board, being the board to whom he is, by law, required to account, wherever the concurrence or authority of such governing board is required with reference to the making of investment in sinking fund monies or the sale of the securities so purchased.
Okla. Stat. tit. 62, § 545