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HARGIS
UPDATE: We are currently updating the HARGIS map application, cleaning existing HARGIS data, and working our way through the backlog of data (starting with National Register listed properties). We ask for your patience as this work progresses.
The Historic and Architectural Resources Geographic Information System (HARGIS) is the public portal to Illinois’ historic buildings, structures, sites, objects, and districts. First launched in 2003, the database contains properties that have been listed in the National Register of Historic Places, determined eligible for listing, or otherwise surveyed without a determination. An updated version with improved location accuracy for many properties and cleaner data is currently live (Fall 2026), while an altogether new map application will launch in 2027.
HARGIS functions as a research tool, not an up-to-the-minute inventory about every historic and/or architecturally significant property in the state. This tool allows researchers to investigate and review potentially significant properties according to the best data that is available in Illinois' historic preservation office.
Several factors can limit the quality of the data you see in HARGIS:
• Properties may have been demolished since they were surveyed
• Street names or other place names may have changed since a property was surveyed
• Inaccurate or confusing source material/surveys
• Many years of backlog of data entry
The absence of a property from this database does not denote a lack of historic or architectural importance. At the same time, properties included in HARGIS do not necessarily hold a high level of historic or architectural significance and are not assured grants or any other assistance or protection. Additionally, historic properties may exist that have not yet been identified. It may be necessary to contact us for more information and to satisfy local, state, or federal historic preservation requirements.
Questions on survey and National Register data: andrew.heckenkamp@illinois.gov
Reports errors in HARGIS data (with documentation as applicable): bpreston@illinois.edu
Accessing National Register Nominations outside of HARGIS:
National Park Service table download and search tool
