Area Code 779 History:
03/17/2007
Area code 779 was put into service. Area code 779 is an overlay of area code 815.
Counties in Illinois within area code 779 include:
Boone County, Bureau County, Carroll County, DeKalb County, Ford County, Grundy County, Henry County, Iroquois County, Jo Daviess County, Kane County, Kankakee County, Kendall County, La Salle County, Lee County, Livingston County, Marshall County, McHenry County, McLean County, Ogle County, Putnam County, Stephenson County, Whiteside County, Will County, and Winnebago County.
Major cities or places in Illinois within area code 779 include: