How to research a tower in Illinois
Start with the county where the structure is located. Each county page combines a geographic map with a searchable list of registered structures. You can compare ASR numbers, cities, owner names, and reported height before opening the individual technical record.
If you know an ASR number or owner name, use the search box in the site header. Searching directly avoids paging through counties and can reveal records filed under a formal corporate name rather than a familiar brand.
Reading the ownership field
The listed entity is the registrant or owner associated with the imported FCC record. It does not identify every carrier, broadcaster, government agency, or other tenant operating equipment on the structure. For real-estate, legal, engineering, or transaction work, confirm current ownership with the official FCC filing and appropriate local records.
Why totals differ from other tower maps
ASR registration is tied to federal structure requirements, not to whether a site provides cellular service. Many rooftop antennas, small cells, and shorter towers are outside the registry, while some registered structures support broadcast or other non-cellular services. Different datasets therefore produce different totals.