Harper County ZIP Codes

Harper County is a county of Oklahoma.

ZIP codes: 4
Cities & towns: 4
Area codes: 1
Land area: 1,039 sq mi

Every ZIP code in Harper County

738xx

The complete list of Harper County, OK ZIP codes with the city each one delivers to.
ZIP code	City
73834	Buffalo
73848	Laverne
73851	May
73855	Rosston

We do not publish a delivery type (standard, PO box, unique) or a neighbourhood for each ZIP.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 Harper County codes above are listed without a column we would have to invent.

Cities and towns in Harper County

Area codes covering Harper County

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

580 Area code 580

Where Harper County's ZIP codes sit

Each point is the reference point of one Harper 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 Harper 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.