Iroquois County, Illinois

Iroquois County covers 1,117 square miles of land. Below is what the Isopleth API returned at the Census Bureau's interior point for the county (40.74887, -87.83360) on 2026-10-29. The ground sits at 197 m (647 ft) on a 0.5° slope, the mapped soil is poorly drained, it is outside a mapped FEMA floodplain, the nearest 69 kV+ substation is 8.4 km (5.2 mi) away and a major road is 2.4 km (1.5 mi) away. Values describe that one point, not the whole county; look up your own address or coordinates for your site.

Sample point values

Fields with no data at this point are left out. See the field catalog for all 351 fields.

Parcels

Parcel records: not offered in Illinois. No free statewide parcel layer with clear reuse terms. Every point field on this page still works at any coordinate in Illinois; see parcel coverage for the 35 states plus DC we cover.

Look up your own site

curl https://api.isopleth.dev/v1/fetch -H "Authorization: Bearer $ISOPLETH_KEY" \
  -H "Content-Type: application/json" \
  -d '{"lat": 40.748867, "lng": -87.833601, "preset": "site_selection"}'

Or ask your assistant through the MCP server: “Using Isopleth, check flood zone, wetlands, soils and distance to power for [your address in Iroquois County, Illinois].”

Buying land here? Check the Land’s Iroquois County page shows what its $29 report checks, built on these same Isopleth fields.

More in Illinois: McLean County · LaSalle County · Illinois overview · all states