Jefferson County, Illinois

Jefferson County sits right in the middle of southern Illinois. Mount Vernon is the county seat, and you’ve probably driven through it on I-57. It’s where you start to feel the shift from the Midwest to the South.

Farming is big here, but there’s some industry too. The county has about 40,000 people, give or take. Still, grain production and other forms of agriculture are definitely number one here.

Rend Lake is in the south, offering good fishing if you don’t mind the crowds. You’ll see a lot of Cardinals fans here, as it’s closer to St. Louis than Chicago. The oil boom is long gone, but you can still spot some old pump jacks creaking away.

CategoryDetails
County NameJefferson County
County SeatMount Vernon
EtymologyNamed after Thomas Jefferson, the third President of the United States
Cities, Towns, and CommunitiesMount Vernon, Woodlawn, Dix, Waltonville, Ina, Bluford, Bonnie, Nason, Belle Rive, Opdyke, Scheller, Texico, and various other unincorporated communities.
Interstates and HighwaysInterstate 57, Interstate 64, U.S. Highway 37, Illinois Route 15, Illinois Route 37, Illinois Route 142
FIPS Code17-081
Total Area (Land and Water)584 square miles (land: 571 sq mi, water: 13 sq mi)
Adjacent Counties (and Direction)Marion County (North), Wayne County (Northeast), Hamilton County (Southeast), Franklin County (South), Perry County (Southwest), Washington County (West)
Time ZoneCentral Time Zone (CT)
PopulationApproximately 36,500
StateIllinois
Coordinates38.3047° N, 88.9343° W
Major LandmarksCedarhurst Center for the Arts, Jefferson County Historical Village, Rend Lake, Aquatic Zoo Waterpark, Appellate Courthouse Historic District
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