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What county is ZIP code 78631 in?

Updated · Data: U.S. Census Bureau

ZIP code 78631 (Harper, TX) is mostly in Kimble County (48.8% of its land), with parts in Gillespie County and Kerr County.

Which counties is ZIP 78631 in?

CountyShare of land areaChart
Kimble County48.8%
Gillespie County44.3%
Kerr County6.9%

About 3,357 people live in this ZIP code area. Because it crosses a county line, the county depends on the street: check your address.

Is ZIP 78631 a Census ZIP code area?

Yes. A ZIP Code Tabulation Area (ZCTA) is the Census version of a ZIP code; its edges can differ from USPS delivery routes (ZIP code vs ZCTA). Look up another ZIP on the ZIP code to county lookup.

Sources: Census 2020 ZCTA-county relationship file; Gazetteer 2024; GeoNames (CC BY 4.0, post office name); ACS 2019-2023 5-year. Data as of November 1, 2026. Not affiliated with USPS or any government agency.

FAQ

Frequently asked questions

What county is ZIP code 78631 in?
ZIP code 78631 (Harper, TX) is mostly in Kimble County (48.8% of its land), with parts in Gillespie County and Kerr County.
Is ZIP 78631 in Gillespie County?
Partly: about 44.3% of its land is in Gillespie County.
What city is ZIP 78631?
The post office name is Harper.

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