Forest Preserve District of Cook County boundaries. To view or use these shapefiles, compression software and special GIS software, such as ESRI ArcGIS, is required.

The Parcel 2021 feature contains tax parcel polygons for the 2021 property tax assessment at the County. This feature reflects tax parcel polygons as they existed from 1/1/2021 through 12/31/2021. An ESRI Service is available at: https://hub-cookcountyil.opendata.arcgis.com/datasets/34021b4f3b834a69bf737e6c3344888e_0

A complete, historic universe of Cook County parcels with attached geographic, governmental, and spatial data.

When working with Parcel Index Numbers (PINs) make sure to zero-pad them to 14 digits. Some datasets may lose leading zeros for PINs when downloaded.

Additional notes:

• Non-taxing district data is attached via spatial join (st_contains) to each parcel's centroid.
• Tax district data (school district, park district, municipality, etc.) are attached by a parcel's assigned tax code.
• Centroids are based on Cook County parcel shapefiles.
• Older properties may be missing coordinates and thus also missing attached spatial data (usually they are missing a parcel boundary in the shapefile).
• Newer properties may be missing a mailing or property address, as they need to be assigned one by the postal service.
• This dataset contains data for the current tax year, which may not yet be complete or final. Assessed values for any given year are subject to change until review and certification of values by the Cook County Board of Review, though there are a few rare circumstances where values may change for the current or past years after that.
• Rowcount for a given year is final once the Assessor has certified the assessment roll all townships.
• Data will be updated monthly.
• Depending on the time of year, some third-party and internal data will be missing for the most recent year. Assessments mailed this year represent values from last year, so this isn't an issue. By the time the Data Department models values for this year, those data will have populated.
• Current property class codes, their levels of assessment, and descriptions can be found on the Assessor's website. Note that class codes details can change across time.
• Due to discrepancies between the systems used by the Assessor and Clerk's offices, tax_district_code is not currently up-to-date in this table.

Read about the Assessor's 2025 Open Data Refresh.

Cook County GIS Department map of municipal boundaries in Cook Cook County, Illinois in PDF format. Includes major streets, waterbodies, rail, Cook County Forest Preserve, and municipal boundaries.

2022 Cook County 1 ft. elevation contours for PLSS Township Area 18 Data is derived from 2022 lidar. If you plan on downloading this dataset it is recommended to use the File Geodatabase option. The shapefile format may not work for larger datasets. Abstract: One-foot interval contours are generated from a two-foot two-pass gridded surface created from the ground (class = 2) and road surface (class = 11) classified lidar points and the hydro breaklines. Purpose: This task is for providing a spring 2022 leaf-off and snow-free high-density lidar survey over an Area of Interest (AOI) of approximately 1,199 square miles covering Cook County, Illinois (and its surrounds).

Location of hospital point features that are publicly accessible within Cook County. Service published in 2016. Cook County GIS and Cook County Real Estate maintain Cook County Government Facilities. Other Government Facilities, Parks, Hospitals, Schools, and Cemeteries created in 2012, updates by Cook County GIS as provided by other agencies.

The purpose of this dataset is to indicate a central location within (when a single feature) or among all the polygons (when a multi-part feature) that constitute that complete cultural feature area of each school in Cook County, Illinois.

© Cook County GIS Department This layer is a component of GIV Planning Data Layers.

This layer is a component of GIV Hydrology Layers.

This layer contains polygons representing land that is under the jurisdiction of the Illinois Nature Preserves Commission (INPC), being designated either as a Nature Preserve, Nature Preserve buffer, or Land & Water Reserve and lying within the boundaries of the Forest Preserve District of Cook County. Actual nature preserve boundaries may vary slightly from GIS polygons shown and should be verified with legal descriptions provided by INPC and Cook County Recorder of Deeds. For more information on Illinois Nature Preserves and the INPC, please visit: Illinois Nature Preserves Commission WebsiteSource data is maintained by the Forest Preserve District's Planning and Development Department (GIS Section) and uploaded to this layer daily.

Cook County GIS Dept map of Commissioner District 3.

The TIGER/Line shapefiles and related database files (.dbf) are an extract of selected geographic and cartographic information from the U.S. Census Bureau's Master Address File / Topologically Integrated Geographic Encoding and Referencing (MAF/TIGER) Database (MTDB). The MTDB represents a seamless national file with no overlaps or gaps between parts, however, each TIGER/Line shapefile is designed to stand alone as an independent data set, or they can be combined to cover the entire nation. Face refers to the areal (polygon) topological primitives that make up MTDB. A face is bounded by one or more edges; its boundary includes only the edges that separate it from other faces, not any interior edges contained within the area of the face. The Topological Faces Shapefile contains the attributes of each topological primitive face. Each face has a unique topological face identifier (TFID) value. Each face in the shapefile includes the key geographic area codes for all geographic areas for which the Census Bureau tabulates data for both the 2020 Census and the annual estimates and surveys. The geometries of each of these geographic areas can then be built by dissolving the face geometries on the appropriate key geographic area codes in the Topological Faces Shapefile.

Cook County Municipalities layer displays the boundaries of all municipalities within Cook County, IL.

© Cook County GIS Department This layer is a component of Boundary data layers for the Green Infrastructure Atlas.

© Calumet Stormwater Collaborative & South Suburban Mayors and Managers Association

Fishing lakes in Cook County with contours. To view or use these shapefiles, compression software and special GIS software, such as ESRI ArcGIS, is required

Cook County GIS Dept map of Commissioner District 12

4-Band aerial imagery flown in 2024 for Cook County, IL at 6 inch pixel resolution. It is recommended that the GeoService URL is used for GIS applications, rather than downloading data.

Cook County GIS Dept map of Commissioner District 17

Cook County GIS Dept map of Commissioner District 1.

Cook County GIS Dept map of Commissioner District 5

Hydrographic data was collected for all of Cook County. Significant flowing and standing water features that were visible on the aerial photography were stereocompiled from 1998 aerial photography. The hydrographic midline data set represents, as a single line, the interpreted midline of flowing water features as seen on the aerial photography. The hydrographic midline data layer is used to show the location of the midline of natural drainage features, and is connected to polygonal (standing) hydrographic features such as lakes and ponds. The midline data layer also includes drainage features less than five feet in width, which were not included in the polygon hydrography data set. Midlines were added to water bodies such as double-line rivers to maintain the linear connectivity of the hydrographic network. Where the course of linear features (such as streams and rivers) in the hydrographic midline layer could not be compiled photogrammetrically due to being obscured by other features (such as vegetation or shadows), the obscured line segment was coded as "interpreted". In some cases, a flowing water feature may have run through an underground drain or culvert or its course otherwise obscured from view on the aerial photography. For such cases, in order to maintain linear connectivity of the features, its path was also interpreted and coded as such. Some hydrographic data was provided by the City of Chicago and incorporated into this data layer. These hydrographic data layers are modeled and stored as a network coverage containing polygons and/or lines. This midline data layer was created out of need by Cook County to develop a hydrographic layer in which water features are represented as single lines. The intended primary use of this data layer is for small-scale mapping and networking. The hydrographic midline layer was intersected with the street midline and railroad data layers to create nodes in the coverage model. It was also intersected with the bridge polygon data layer. Where hydrographic midline segments fall within a bridge polygon, they have been given a grade separation code of zero (0) to indicate the water level is technically "at grade". Hydrographic attributes include feature name, tax map name, and type. The primary source of the attribute information was the Cook County Highway Department database. Hydrographic names and alias IDs are linked to lookup tables based on the hydrographic name ID attribute.

Panchromatic aerial imagery flown in 1998 for Cook County, Illinois at 6 inch pixel resolution.It is recommended that the GeoService URL is used for GIS applications, rather than downloading data.