Okla. Stat. tit. 69 § 636.1
There is hereby created in the State Treasury a revolving fund to be known and designated the "County Road Machinery and Equipment Revolving Fund", which shall consist of all appropriations and deposits made for the purposes hereinafter designated and shall also include all proceeds resulting from the lease, lease-purchase, sale or resale of equipment purchased out of monies in the revolving fund. The revolving fund shall be a continuing fund and shall be nonfiscal in character. The fund shall be invested in whatever instruments are authorized by law for investments by the State Treasurer and the interest earned by any investment of monies from the fund shall be credited to the fund for expenditure as provided by law.
Okla. Stat. tit. 69, § 636.1