Membership on the Board shall consist of those persons duly elected to serve on the Board of Trustees of River Forest Township. Terms for members of the Board shall coincide with their respective terms of office as members of the Board of Trustees of River Forest Township. 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 200/230-20