Okla. Stat. tit. 70, § 70-612

Until such time as said funds may be safely and advantageously

invested in the securities mentioned in the preceding section, said

Commissioners of the Land Office are hereby authorized and empowered

to deposit said sums in such banks or trust companies as they may

select, but shall in every case take as security for such deposits

the following classes of securities and no others: Bonds of the

State of Oklahoma, bonds of the counties, school districts, cities

and towns of this state, state and county warrants, and approved

State, county and municipal bonds of other states, bonds of the

United States, first mortgages on real estate, warrants or other

legal evidence of indebtedness authorized by law to be issued by

municipalities in payment of paving, sewer, waterworks, electric

light, or other public indebtedness and for the payment of which a

special tax is authorized to be levied and collected, and as

additional security on any deposit which said Board may make the

said Commissioners of the Land Office shall have authority to accept

surety companies or trust companies as sureties, but in each case

said Board of Land Commissioners shall accurately investigate the

value of securities offered for such deposits: Provided, however,

that such surety company or trust company shall neither be in any

manner interested directly or indirectly in any bank or trust

company for which it becomes additional surety; nor shall any

surety, bonding or trust company be accepted as additional surety

that has more than one-fourth (1/4) of its paid capital invested in

bank stock. The said Board of Land Commissioners may, whenever they

deem it advisable require additional securities after a deposit is

made as they deem necessary to secure the safety of the deposit.