United States (USA) - Illinois - counties of Adams; Alexander; Bond; Brown; Bureau; Calhoun; Carroll; Cass; Christian; Clinton; Fulton; Greene; Hancock; Henderson; Henry; Jackson; Jersey; Jo Daviess; Knox; Lee; Logan; Macoupin; Madison; Marshall; Mason; McDonough; Menard; Mercer; Monroe; Montgomery; Morgan; Ogle; Peoria; Perry; Pike; Pulaski; Putnam; Randolph; Rock Island; Sangamon; Schuyler; Scott; St Clair; Stark; Stephenson; Tazewell; Union; Warren; Washington; Whiteside; Winnebago; Woodford.

@misc{6457_area_of_use
author=geoepsg_dataset Contributors",
title="United States (USA) - Illinois - counties of Adams; Alexander; Bond; Brown; Bureau; Calhoun; Carroll; Cass; Christian; Clinton; Fulton; Greene; Hancock; Henderson; Henry; Jackson; Jersey; Jo Daviess; Knox; Lee; Logan; Macoupin; Madison; Marshall; Mason; McDonough; Menard; Mercer; Monroe; Montgomery; Morgan; Ogle; Peoria; Perry; Pike; Pulaski; Putnam; Randolph; Rock Island; Sangamon; Schuyler; Scott; St Clair; Stark; Stephenson; Tazewell; Union; Warren; Washington; Whiteside; Winnebago; Woodford.",
"url="http://www.opengis.net/def/crs/EPSG/0/6457_area_of_use",
note="[Online; documentation generated at 2025-10-19]"}