Okla. Stat. tit. 60, § 60-175.10: Deposits by corporate trustee with itself - Security

A corporate trustee may deposit with itself trust funds in

checking and savings accounts, savings certificates, certificates of

deposit, and any other type of demand or time deposit, provided it

maintains under control of its trust department, if it has a trust

department separate from its banking department, as security for

such deposit a separate fund consisting of securities legal for

trust investments which have at all times during the deposit a total

market value exceeding the amount of the deposit. No such security

shall be required to the extent said deposit is guaranteed by or

under state or federal law.

The separate fund of securities shall be marked as such.

Withdrawals from or additions to it may be made from time to time,

as long as the required value is maintained. The income of such

securities shall belong to the corporate trustee.