Geographic Regions and Area Codes

Area Code 861 is located in Illinois and serves as an overlay to the existing 309 area code. This area code covers a significant portion of west-central Illinois, including major cities such as Peoria, Bloomington-Normal, and the Quad Cities (Moline, East Moline, and Rock Island). The region includes 20 counties, such as Peoria, Knox, Henry, McLean, Whiteside, and Bureau, among others. The overlay was implemented to meet the increasing demand for phone numbers due to population growth and the proliferation of mobile devices and Internet-based services. Ten-digit dialing is now mandatory for all calls within the 309 and 861 area codes, including local calls.

Key regions covered by Area Code 861:

  • Peoria
  • Bloomington-Normal
  • Quad Cities (Moline, East Moline, Rock Island)
  • 20 counties including Peoria, Knox, Henry, McLean, Whiteside, and Bureau