The boards of county commissioners in all counties of the State of Oklahoma having a population in excess of two hundred thousand (200,000), as shown by the last preceding or any future regular Federal Decennial Census, be, and they are hereby empowered to appoint such employees and assistants, as shall be necessary for said board to properly accomplish the statutory and lawful duties and functions of said board, and who shall serve during the pleasure of said board on a whole or part-time basis at such rates of salary or pay as may be agreed upon by said board.
Okla. Stat. tit. 19, § 452