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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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Grant County ZIP Codes

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

County State ZIP Code City Area Codes
Grant County OR 97865 Mount Vernon 458, 541
Grant County OR 97869 Prairie City 458, 541
Grant County OR 97873 Seneca 458, 541
Grant County SD 57216 Big Stone City 320, 605
Grant County SD 57246 Labolt 605
Grant County SD 57251 Marvin 605
Grant County SD 57252 Milbank 320, 605
Grant County SD 57253 Milbank 605
Grant County SD 57256 Ortley 605
Grant County SD 57259 Revillo 320, 605
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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.