70 ILCS 1845/16
The Governor shall appoint 3 members of the Board and the President of the Village of Seneca shall appoint 3 members of the Board, and the Chairman of the La Salle County Board, shall appoint one member of the Board. All initial appointments shall be made within 60 days after this Act takes effect. Of the 3 members initially appointed by the Governor, one shall be appointed for an initial term expiring June 1, 1962, one for an initial term expiring June 1, 1963 and one for an initial term expiring June 1, 1964. The terms of the members initially appointed by the President shall expire June 1, 1964. The term of the member initially appointed by the Chairman of the La Salle County Board shall expire June 1, 1964. At the expiration of the term of any member, his successor shall be appointed by the Governor or the President or the Chairman of the County Board of La Salle County in like manner and with like regard to place of residence of the appointee, as in the case of the appointments for the initial terms except that after September 30, 1973, appointments to be made by the Chairman of the county board shall be made with the advice and consent of the county board.
After the expiration of initial terms each successor shall hold office for the term of 3 years beginning the first day of June of the year in which the term of office commences. In the case of a vacancy during the term of office of any member appointed by the Governor, the Governor shall make an appointment for the remainder of the term vacant and until a successor is appointed and qualified. In case of a vacancy during the term of office of any member appointed by the President, the President shall make an appointment for the remainder of the term vacant and until a successor is appointed and qualified. In case of a vacancy during the term of office of any member appointed by the Chairman of the County Board of La Salle County, the Chairman of the County Board of La Salle County shall make an appointment with the advice and consent of the county board for the remainder of the term vacant and until a successor is appointed and qualified. The Governor, President and the Chairman of the County Board of La Salle County shall certify their respective appointments to the Secretary of State. Within 30 days after certification of his appointment, and before entering upon the duties of his office, each member of the Board shall take and subscribe the constitutional oath of office and file it in the office of the Secretary of State.
70 ILCS 1845/16