Reference Data Rate Center Directory WILLOWHILL, IL Rate Center WILLOWHILL — IL Data last updated: March 10, 2026 LATA 978 State IL Area Codes 1 Exchanges (NXX) 1 Carriers 1 Coordinates 38.9958759, -88.02253490000001 Area Codes 618 Top Carriers Carrier OCN NXX Count FRONTIER NORTH, INC. - IL 1015 1
