Grant County ZIP Codes

Grant County is a county of Oregon.

ZIP codes: 10
Cities & towns: 10
Area codes: 2
Land area: 4,528 sq mi

Every ZIP code in Grant County

978xx

The complete list of Grant County, OR ZIP codes with the city each one delivers to.
ZIP code	City
97817	Bates
97820	Canyon City
97825	Dayville
97845	John Day
97848	Kimberly
97856	Long Creek
97864	Monument
97865	Mount Vernon
97869	Prairie City
97873	Seneca

We do not publish a delivery type (standard, PO box, unique) or a neighbourhood for each ZIP. USPS delivery-type products are licensed, and no clean-rights source maps ZIP codes to neighbourhoods — so the Grant County codes above are listed without a column we would have to invent.

Cities and towns in Grant County

A further 2 places in Grant County appear in the postal source without a page of its own; their codes are in the table above and each one links to its own page.

Area codes covering Grant County

Telephone and postal boundaries are drawn by different bodies, so these codes overlap the county without matching its edges.

Where Grant County's ZIP codes sit

Each point is the reference point of one Grant County ZIP code, plotted from its record coordinates. The outline is the convex envelope of those points — a footprint, not a boundary.

Reference points and footprint
Not an official NANPA boundary
Not a USPS delivery area

Scope every ZIP code recorded in Grant County. Source GeoNames US postal codes (2026-07 postal dump), Census 2024 county Gazetteer (2024 Gazetteer) and geoinfo-dataset (full_dataset) ZIP→NPA (2018 snapshot). Updated 16 July 2026. The outline is a convex envelope of ZIP reference points, not a jurisdiction boundary.