A Zoning Plan shall be established pursuant to this chapter containing the designations, locations and boundaries of the various zone districts delineated on sectional district maps, each map covering one square mile. An index map to the sectional district maps shall be provided. The Zoning Plan and maps shall be considered an integral part of this chapter. (Ord. 560, 7/14/58; 1891, 6/19/73; 2761, 9/4/79; 2824, 12/4/79; 3186, 1/12/82; 3344, 11/23/82; 3432, 8/23/83)