779 Area Code

Primary cities: Rockford, Joliet, De Kalb, Frankfort, Kankakee ... all cities

Cities: Ashton, Beaverville, Belvidere, Braidwood, Byron, Capron, Chatsworth, Cherry Valley, Cissna Park, Coleta, Crescent City, Creston, Crystal Lake, Danforth, De Kalb, Depue, Dixon, Donovan, Durand, Dwight, Fairbury, Flanagan, Forrest, Frankfort, Franklin Grove, Freeport, Galena, Garden Prairie, Genoa, Grand Ridge, Granville, Graymont, Hanover, Harding, Harvard, Herscher, Hinckley, Hooppole, Joliet, Kankakee, Kempton, Kinsman, Kirkland, La Salle, Lanark, Leland, Lena, Lisbon, Long Point, Lostant, Magnolia, Malta, Manteno, Maple Park, Marengo, Martinton, Mazon, Mchenry, Mendota, Milford, Monroe Center, Morris, Mount Morris, New Lenox, New Milford, Newark, Oglesby, Onarga, Paw Paw, Pecatonica, Piper City, Plainfield, Polo, Pontiac, Princeton, Reddick, Richmond, Rochelle, Rock Cut, Rockford, Rockton, Roscoe, Rutland, Sandwich, Shabbona, Sheffield, Sheldon, Sheridan, South Beloit, Spring Grove, Spring Valley, St. Anne, Sterling, Steward, Stockton, Streator, Sycamore, Thomas, Toluca, Tonica, Union, Verona, Warren, Watseka, Wenona, Wilmington, Winnebago, Wonder Lake, Woodland, Woodstock