Okla. Stat. tit. 62, § 62-72.5: Securities eligible for securing public deposits

A. For purposes of securing public deposits, the State

Treasurer may accept as collateral only those securities and other

instruments listed below. To insure the safety of public funds, the

State Treasurer may establish standards which restrict, or limit

further, any of the types or classes of securities or instruments

listed below which may be accepted. The State Treasurer may select

the following securities and instruments for the purpose of securing

public deposits:

1. Obligations, including letters of credit of the United

States Government, its agencies and instrumentalities;

2. Obligations of this state or of a county, municipality, or

school district of this state or of an instrumentality of this state

or a county, municipality or school district of this state;

3. General obligation bonds of any other state of the United

States; and

4. A surety bond if:

a. subject to the terms and conditions of the bond, it is

irrevocable and absolute,

b. the surety bond is issued by an insurance company

authorized to do business in Oklahoma,

c. the issuer of the surety bond does not provide surety

bonds for any one financial institution in an amount

that exceeds ten percent (10%) of the surety bond

insurer's policyholders' surplus and contingency

reserve, net of reinsurance, and

d. the claims-paying ability of the authorized insurance

company is rated, at all relevant times, in the

highest category by at least two nationally recognized

rating agencies acceptable to the State Treasurer.

B. A financial institution may substitute different forms of

collateral from time to time, provided that each meets the

requirements of this section and the rules and regulations of the

State Treasurer.