This is a compilation of municipal boundaries obtained from CMAP counties in 2020 (no outside-of-region files were updated). All features have been dissolved into single (often multi-part) polygons regardless of how many counties they are in. Topological clean-up has removed overlaps (this happens not only between county files, but within certain, less-diligent counties as well). Gaps along county boundaries for multi-county towns were cleaned up as well. Data are primarily from 2020. Sources and acquisition months for the individual counties are listed below:

• Cook: Cook Central data portal, April 2020

• DuPage: DuPage GIS FTP download, June 2020

• Kane: Kane GIS CD, March 2020

• Kendall: Kendall GIS website, March 2020

• Lake: Lake Data Portal, March 2020

• McHenry: McHenry GIS CD, July 2020

• Will: Will County "Available Data" website, March 2020

• DeKalb: DeKalb County GIS, October 2017

• Grundy: Grudy County GIS, August 2016

• Boone, LaSalle, and Kankakee: Census TIGER 2016