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U.S. ZIP Codes Database 2026

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Hardin County ZIP Codes

Browse all ZIP Codes, cities, and associated area codes registered in Hardin County.

County State ZIP Code City Area Codes
Hardin County IA 50601 Ackley 319, 641
Hardin County IA 50627 Eldora 515, 641
Hardin County IA 50672 Steamboat Rock 641
Hardin County IL 62919 Cave In Rock 270, 364, 618
Hardin County IL 62931 Elizabethtown 270, 364, 618
Hardin County IL 62947 Herod 618
Hardin County IL 62955 Karbers Ridge 618
Hardin County IL 62982 Rosiclare 270, 364, 618
Hardin County KY 40121 Fort Knox 270, 364, 502
Hardin County KY 40122 Fort Knox 502
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About U.S. ZIP Codes

ZIP codes are a United States Postal Service system introduced in 1963 to make mail routing more accurate and efficient. The standard format uses five digits, while ZIP+4 adds four more digits for a more precise delivery segment.

ZIP codes cover the United States, its territories, military mail routes, and other USPS delivery points. This directory organizes that data for practical lookup by ZIP code, city, county, and state.