Illinois · FIPS 17189 · County seat: Nashville
Washington County, IL GIS & Parcel Viewer
Here is the direct link to the county parcel map covering Washington County, IL: Washington County Portico map. Below you'll find basic facts about the county, steps for using the viewer, and nearby counties.
Open the Washington County parcel map ↗
Opens portico.sidwellco.com in a new tab. We link out and never embed or copy parcel data.
Map and county facts
| Official map | Washington County Portico map |
|---|---|
| Type | County-run map |
| Website | portico.sidwellco.com |
| Access | Free, no login (checked Oct 2026) |
| County seat | Nashville |
| Population | 13,536 (2023 Census Bureau estimate) |
| Land area | 563 sq mi |
| FIPS code | 17189 |
About the official source
It is a county-level map: Washington County or the company it hires keeps the parcel layer up to date. Our October 2026 check found the map open to the public, with no account or payment needed.
Searching for a parcel, step by step
- Open the official link; the viewer runs on Esri's ArcGIS platform.
- Find the search control and type in a street address or parcel ID, or zoom in by hand.
- Click a parcel to see the attributes the publisher shares.
- Use any layer or basemap tools to add aerial imagery or other map layers.
Many parcel sites expect owner names last name first. If a full name finds nothing, try just the surname.
The county in brief
Census Bureau figures put Washington County at about 13,536 people (2023 estimate) on roughly 563 square miles of land, which is about 24 residents per square mile. By population it ranks 76th of 102 counties in Illinois. Nashville serves as the county seat.
Nearby parcel maps
Parcels close to the edge of Washington County can fall in the next county over. Neighboring counties:
Maps vs. surveys
Keep in mind that a GIS parcel layer is a tax map, not a survey. For exact boundaries, look at the recorded deed and plat or hire a licensed land surveyor.