A land plat is a map that engineers, planning departments and zoning boards use for planning purposes. According to the Illinois State Library, the plat map system dates back to the late 1700s, and detailed local and state maps are archived by federal offices. They are drawn to scale and show how land parcels are separated and divided. The hard copies are usually available at the town/city hall and would cover an entire table. Municipal engineers are also likely to use the Geographic Information System (GIS) that would have digital plats in addition to other maps for pinpointing infrastructure and zoning designations. Some of these maps even may be available to the public online.
Visit the websites for your town and county and search the records or maps section for plats. Plat maps may be incorporated into the assessment listings.
Check out a variety of web sites that sell plat maps online. Make sure the maps are detailed and have markings for town boundaries and bodies of water.
Stop at the town or city hall of country office building and ask to see the plat map for the area you are interested in. There should be large, hard copies available and digitized maps. If the municipality has a GIS system, an employee can narrow in on the specific information you are looking for, ranging from shapes of lots in a subdivision to the actual locations of manholes.