Cook County Open Data
Socrata open data catalog for Cook County, IL.
DuPage County GIS
ArcGIS open data portal for DuPage County, IL containing datasets and applications.
McLean County GIS
ArcGIS site for McLean County, IL containing web maps and web apps.
Lake County Illinois Open Data Portal
ArcGIS open data portal and records hub for Lake County, IL containing data, records, maps, apps, and more.
Peoria County GIS Open Data Portal
On Peoria County, IL ArcGIS open data website you can discover our interactive map applications, digital maps, and GIS data. You can search, visual...