779 Area Code

The 11 central offices below make up area code (779) in Illinois.

• (779) 220
• (779) 201
• (779) 500
• (779) 209
• (779) 400
• (779) 200
• (779) 537
• (779) 207
• (779) 236
• (779) 861
• (779) 279

These exchanges encompass the following IL cities:

• Crystal Lake
• La Salle
• Rockford
• Sandwich
• Dekalb
• Kankakee
• Dixon
• Joliet

Learn more: Area code 779 at Wikipedia