Okla. Stat. tit. 69 § 319
This Code shall not affect the status, rights and privileges accrued under the State Merit System of Personnel Administration, or the Oklahoma Public Employees Retirement System, to persons serving as employees of the Department of Highways created by 69 O.S.1961, Section 20.1, when this Code becomes effective, and continuing to serve as employees of the Department created by Section 301 of this Code. For the purposes of 74 O.S.1961, Sections 801 - 839, as amended, and Chapter 50, Oklahoma Session Laws 1963 (74 O.S. Supp. 1965, Sections 901 - 928), the former Department and the latter Department shall be deemed to be a single continuing department or agency of the state government; and persons serving as employees of the former Department and continuing as employees of the latter Department shall be entitled to the same status, rights and privileges that they would have had if the former Department had remained in existence.
Okla. Stat. tit. 69, § 319