Cook County Municipal Boundary Change

About this Project

The Cook County Recorder of Deeds documents all real estate transactions that occur in the County and all resulting municipal boundary changes. As part of a larger team tasked with creating a definitive spatial database of these boundaries, Urban GIS digitized paper records – maps and legal descriptions – of all boundary changes since the founding of Cook County. Urban GIS worked alongside Recorder of Deeds staff to locate, document, and organize legacy boundary change records. This step was critical in preparing the necessary data to be converted into GIS format. Urban GIS also performed quality assurance of the boundary geodatabase as it was being built.

Urban GIS was tasked with taking municipal plat maps and accompanying legal pages, often in poor condition, and transform them into digital images that could be used to draw an accurate GIS database. This entailed strategically documenting these records using a number of tools including scanners, cameras and GIS software.

Accurate and thorough documentation is a requirement for building a spatial dataset. For this project, flawed documents would result in flawed decision-making about taxation, future border changes, and demographic estimates at the local, state, and federal levels. This inventory provided by Urban GIS ensures that all original and relevant information is clearly translated into a definitive database of Cook County community boundaries.