Bedrock Geology of Champaign County, Illinois, map layers (shapefiles). Layers included: 1) Champaign County bedrock units. 2) Champaign County bedrock surface contours. Contour interval of 25 feet. 3) Colchester coal surface contours. Contour interval of 50 feet. 4) Kimmswick Limestone top contours, in the Mahomet dome area. Contour interval of 20 feet. 5) New Albany shale base contour. Contour interval of 100 feet.

IL Political Townships. This data source is updated by the Illinois Department of Revenue.

This layer is a component of Illinois Reference Layers.

© Illinois State Geological Survey

This geodatabase serves two purposes: 1) to provide State of Illinois agencies with a fast resource for the preparation of maps and figures that require the use of shape or line files from federal agencies, the State of Illinois, or the City of Chicago, and 2) as a start for social scientists interested in exploring how geographic information systems (whether this is data visualization or geographically weighted regression) can bring new meaning to the interpretation of their data. All layer files included are relevant to the State of Illinois. Sources for this geodatabase include the U.S. Census Bureau, U.S. Geological Survey, City of Chicago, Chicago Public Schools, Chicago Transit Authority, Regional Transportation Authority, and Bureau of Transportation Statistics.

Illinois is at the center of the nation’s rail network. It has a comprehensive rail network consisting of approximately 9,982 miles of railroad tracks, 7,792 of which are operated by Class I railroads – primarily BNSF Railway and the Union Pacific Railroad (UP). Class I railroads are large freight companies, Class II and Class III are small regional railroad companies. The remaining 2,190 miles of track are operated by Class III short line or regional railroads. A total of 41 railroads currently operate in Illinois. They range in size from a short one-mile interstate carrier to larger railroads extending from Illinois to the West and East Coasts, Gulf of Mexico, Canada, and Mexico. Seven are freight (Class I) carriers and 34 are regional, local, switching and terminal railroads. In all, 40 railroads are able to provide service from Illinois to every part of the United States. Chicago is the largest US rail gateway and there is another major rail center located in East St. Louis. Rail’s importance to both Chicago and the state is highlighted by the fact that over 1,300 freight, passenger and commuter trains pass through the Chicago region every day and, in 2011, Illinois ranked first in the nation in terms of rail freight volume at 490.4 million tons.Updated from IDOT Illinois Railroads MapBase source 9/19/2019

Download In State Plane Projection Here ** In addition to the Tax Parcel polygons feature class, the hyperlink download above also contains a parcel point data layer ** Parcel boundaries are developed from deeds, plats of subdivision and other legal documents going back to the mid 1800's, following generally accepted practices used in Public Land Survey System states, and following guidelines established by the Illinois Department of Revenue and the International Association of Assessment Officials. Lake County's parcel coverage is based on resolving the accumulated evidence of all of the legal documents surrounding a particular parcel or subdivision, and not the result of a countywide resurvey. These parcel boundaries are intended to be a visual inventory of property for tax and other administrative purposes; they are not intended to be used in place of an on-site survey or for the precise determination of property corners or PLSS features based on GIS coordinates. In Illinois, only a registered professional land surveyor is authorized to determine boundary locations. Included are the tax parcel boundaries, represented as polygons and centroids, for all changes resulting from legal records submitted to the Recorder of Deeds up to December 31st of the preceding year, as well as any court orders, municipal annexations and other transactions which impact the tax parcel boundaries. NOTE: The ONLY attribute included is the Property Index Number, or PARCEL_NUM. Additional assessment attribute data can be downloaded here This parcel layer is used for tax assessment purposes and for a variety of other local government functions. It changes often, both spatially and in its attribution, based on divisions or consolidations, the sale of property and other transactions. Example: PIN 08-17-304-014 can be interpreted as follows: Township 08, Section 17, Block 304, Parcel 014. Note that the first digit of block, "3" in this example, signifies that the parcel lies in quarter section 3. The quarter sections are labeled from 1 through 4, representing the northwest, northeast, southwest and southeast quarter sections, respectively. Update Frequency: This dataset is updated on a weekly basis.

Download In State Plane Projection Here. ** The Street Centerline feature class now follows the NG911/State of Illinois data specifications including a StreetNameAlias table. The download hyperlink above also contains a full network topology for use with the Esri Network Analyst extension ** These street centerlines were developed for a myriad of uses including E-911, as a cartographic base, and for use in spatial analysis. This coverage should include all public and selected private roads within Lake County, Illinois. Roads are initially entered using recorded documents and then later adjusted using current aerial photography. This dataset should satisfy National Map Accuracy Standards for a 1:1200 product. These centerlines have been provided to the United States Census Bureau and were used to conflate the TIGER road features for Lake County. The Census Bureau evaluated these centerlines and, based on field survey of 109 intersections, determined that there is a 95% confidence level that the coordinate positions in the centerline dataset fall within 1.9 meters of their true ground position. The fields PRE_DIR, ST_NAME, ST_TYPE and SUF_DIR are formatted according to United States Postal Service standards. Update Frequency: This dataset is updated on a weekly basis.

Download In State Plane Projection Here. Boundaries for electing senators to the Illinois Senate as established by that body. Update Frequency: This dataset is updated on a weekly basis.

Illinois Boundary-Based LayersThis dataset contains boundary and administrative layers for the state of Illinois, supporting regional planning, infrastructure development, and government decision-making. The dataset includes various geographic divisions, such as counties, municipalities, and economic regions.Layers Included:Counties – Official county boundaries in Illinois.Municipal Boundaries – City, town, and village limits within the state.Economic Development Regions – Defined regions for economic planning and policy initiatives.Legislative & Administrative Districts – Political and governance boundaries used for state and local representation.This feature dataset provides essential boundary and administrative layers for the state of Illinois, supporting regional planning, infrastructure development, broadband expansion, and government decision-making. The dataset includes official jurisdictional and economic boundaries, ensuring accurate spatial data for state agencies, municipalities, and economic planners. These layers are used for broadband infrastructure mapping, public policy implementation, zoning regulations, and funding allocation, making them a critical resource for data-driven decision-making across various sectors. Layers Included:

Census Blocks (2010) – Used for demographic analysis and broadband eligibility mapping. Congressional Districts (2020 Redistricting) – Updated federal legislative boundaries for policy analysis and representation. County Boundaries – Official county jurisdictional limits used for statewide and local planning. Electric Utility Boundaries – Defines service areas of electric providers for infrastructure coordination. Federal Lands – Identifies federally owned properties, including national parks, military bases, and protected lands. Opportunity Zones (Tracts) – Displays designated economic development zones to encourage investment and business growth. School Districts (E-Rate) – Represents school district boundaries to support education funding and broadband initiatives. State House Districts (2020 Redistricting) – Updated Illinois State House legislative boundaries. State Senate Districts (2020 Redistricting) – Updated Illinois State Senate legislative boundaries. Village Boundaries – Defines city, town, and village limits across Illinois. Townships/Precincts, Cities, and Villages – Displays townships and voting precincts; users can zoom in for detailed city and village boundaries.

Usage & Integration:

Supports State & Local Planning – Provides official jurisdictional boundaries for zoning, economic development, and public infrastructure projects. Broadband Expansion & Utility Coordination – Used for mapping broadband availability and planning utility infrastructure. Legislative & Policy Applications – Assists in election planning, representation, and legislative resource allocation. Public & Private Sector Use – Utilized by government agencies, municipalities, businesses, and researchers for geospatial analysis.

Change Log:

3/14/2025 - Updated item details with significant elaboration on what is included in this service. 1/30/2025 – Updated county and municipal boundaries to reflect recent administrative changes. 1/15/2025 – Added electric utility boundaries to support broadband and infrastructure coordination. 12/20/2024 – Refined opportunity zones and federal lands data for economic planning purposes. 11/10/2024 – Adjusted state and congressional district boundaries to match official redistricting updates. 10/05/2024 – Initial dataset release with core administrative and planning layers.

Access & Contact:

Dataset Access: Available in ArcGIS Online

This Illinois Boundary-Based Layers dataset provides a comprehensive and authoritative resource for regional planning, broadband expansion, utility coordination, and legislative mapping across the state.

Download In State Plane Projection Here. Sanitary Districts provide sewage collection and treatment within their service areas. Update Frequency: This dataset is updated on a weekly basis.

State of Illinois Obesity Percentages by County. Explanation of field attributes: Obesity - The percent of each Illinois county’s population that is considered obese from the 2015 CDC BRFSS Survey.

Illinois Department of Transportation District Boundaries

Suburban Cook County Election Precincts maintained by the Cook County Clerk's Election Department. Not included are the City of Chicago Election Precincts which are maintained by the Chicago Board Of Elections. An ArcGIS Service is available at: https://hub-cookcountyil.opendata.arcgis.com/datasets/0e91b48d49744346be343f0cb99d25bd_0/

Voting District Project of the Census Redistricting Data Program commenced in Summer of 2017 to establish the state’s Voting precincts within the bureau’s tiger geography. The initial phase used the Bureau’s GUPS plugin for QGIS to update the districts from the 2010 round, and then a secondary verification phase took place to ensure the updated voting districts were properly enacted into Tiger geographic files. A post census effort took place in December 2021 to cut the number of precincts down countywide to 1430. Election Data Services conducted Phase 2 of the Census Redistricting Data Program for the State of Illinois, as well as implemented changes made post census in Cook County.

Precincts are updated as needed before every election by the Cook County Clerk's Elections Department.

Illinois Broadband PAU Data utilized in the PAU Selector Tool. This file geodatabase (FGDB) contains Premises Addressable Unit (PAU) data for Illinois as of January 21, 2025. It serves as an archival dataset, preserving PAU records from this date for historical reference, validation, and analysis. This dataset is primarily used for tracking changes in broadband coverage, funding eligibility, and service availability over time.Change Log:3/3/2025 - Updated item description and metadata.1/23/2025 - Updated Data, links, and metadata.1/21/2025 - Created item.Important Links:Illinois Broadband MapIllinois Broadband Hub SiteThe PAU dataset supports various broadband planning efforts, including:Illinois BEAD Challenge Process – Provides reference data for past BEAD challenge submissions and reviews.Broadband Service Availability Analysis – Enables comparison of historical PAU data with updated broadband service areas.Regulatory and Compliance Audits – Ensures accurate tracking of premises classifications for state and federal broadband programs.Public and Private Sector Use – Supports Internet Service Providers (ISPs), state agencies, and local governments in broadband infrastructure planning.Key Data Components:PAU Unique Identifiers – Tracks individual premises with distinct identifiers.Service Availability Status – Identifies locations as served, underserved, or unserved based on broadband speed benchmarks.Geographic Coordinates – Provides precise spatial locations of PAUs for mapping and analysis.Historical Data Reference – Retains PAU records as of January 21, 2025, for archival and validation purposes.Usage & Integration:Archive Purposes: Maintains historical PAU data for reference and validation.Broadband Mapping & Planning: Supports state and local broadband expansion initiatives.Challenge Process Validation: Ensures historical PAU classifications are accessible for audits and reviews.Geospatial Analysis: Compatible with ArcGIS and other GIS platforms for visualization and spatial analysis.Access & Contact:File Format: File Geodatabase (.gdb)Data Status: Archived dataset – not actively updatedContact: Illinois Broadband Office | 📧 broadband@illinois.govMore Info: Illinois Broadband Program WebsiteThis PAU archive dataset provides a historical reference for broadband service availability in Illinois as of January 21, 2025, supporting data integrity, compliance tracking, and broadband planning efforts.

Download In State Plane Projection Here. Municipal boundaries are based on annexations, court orders and other legal documents filed in the office of the Recorder of Deeds. Mapping is based on the legal descriptions from those documents, which relate to existing parcel boundaries or to the underlying PLSS. Important attributes include "Type" which contains an "I" if the polygon represents an incorporated area, and a "U" if unincorporated. The municipality name for "I" type polygons is included in the attribute "NAME1." Update Frequency: This dataset is updated on a weekly basis.

Download In State Plane Projection Here. These are the areas for the Community Colleges serving Lake County. Update Frequency: This dataset is updated on a weekly basis.

Download In State Plane Projection Here See the Lake County Soils Documentation for additional information -- including an explanation of data fields. This product includes the United States Department of Agriculture - Natural Resources Conservation Service 2004 Soil Survey data and related information. An intergovernmental funding agreement between the USDA-NRCS, the State of Illinois Department of Agriculture and Lake County made this product possible. This soil information is referred to as SSURGO by NRCS. The spatial (soil polygons) and tabular (physical and chemical properties) data for all soil survey areas are available free from the Web Soil Survey website. Helpful information about soils can be found through the NRCS Illinois website. The McHenry-Lake County Soil and Water Conservation District staff can also provide assistance with questions related to soils.

An in-depth description of the various Political Boundaries GIS data layers outlining terms of use, update frequency, attribute explanations, and more. District data layers include: Lake County Boundary, County Board, Judicial Circuit Court Subcircuits, Political Townships, State Representative Districts, State Senate, Congressional Districts, and Voting Precincts.

Current community area boundaries in Chicago. The data can be viewed on the Chicago Data Portal with a web browser. However, to view or use the files outside of a web browser, you will need to use compression software and special GIS software, such as ESRI ArcGIS (shapefile) or Google Earth (KML or KMZ), is required.

This file is a digital geospatial Environmental Systems Research Institute (ESRI) ArcGIS File Geodatabase Polygon Feature Class representing land use in the seven northeastern Illinois counties (Cook, DuPage, Kane, Kendall, Lake, McHenry and Will). Land use is identified to 60 categories, and was created using county parcel GIS boundaries and Assessor data, along with color orthorectificed aerial photography captured in April, 2010. Land uses were assigned to parcels using a combination of automated and manual techniques, using a variety of reference data sets for land use identification and validation. Parcels were then dissolved on common land uses (to the limits of PLS sections or assessor blocks); polygons were generated for “non-parcel” (water, right-of-way) areas and classified using automated processes, and extnesive topological cleaning was necessary to minimize gap/overlap issues.In addition to this metadata record, additional information can be found in the following documents:2010 Land Use Inventory Classification Scheme2010 Land Use Inventory Geodatabase Schema2010 Land Use Inventory MetadataLANDUSE lookup .csv table to support shapefile downloadsProcess Narrative: Creating the 2010 Land Use Inventory for Northeastern IllinoisProcess Narrative Addendum: Creating Version 2.0Comparison Guide: Differences between the 2010 and 2005 Land Use InventoriesNOTE: Land use polygons are based on county parcel boundaries; special care must be exercised when comparing these data to earlier (2005, 2001, 1990) Inventories, which relied on manual drafting of land use boundaries that would extend to road centerlines. Additionally, the classification scheme was rewritten to accommodate the parcel approach; see the "comparison guide" link above for inter-inventory analysis guidance.