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U.S. ZIP Codes Database 2026

Search by ZIP code, city, county, or state and find clear postal details with maps, time zones, and area code data.

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LaSalle County ZIP Codes

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

County State ZIP Code City Area Codes
LaSalle County IL 61360 Seneca 779, 815
LaSalle County IL 61364 Streator 779, 815
LaSalle County IL 61370 Tonica 779, 815
LaSalle County IL 61371 Triumph 779, 815
LaSalle County IL 61372 Troy Grove 779, 815
LaSalle County IL 61373 Utica 779, 815
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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.