Dewey County ZIP Codes

Dewey County is a county of South Dakota.

ZIP codes: 7
Cities & towns: 7
Area codes: 1
Land area: 2,302 sq mi

Every ZIP code in Dewey County

576xx

The complete list of Dewey County, SD ZIP codes with the city each one delivers to.
ZIP code	City
57625	Eagle Butte
57630	Glencross
57633	Isabel
57636	Lantry
57652	Ridgeview
57656	Timber Lake
57661	Whitehorse

We do not publish a delivery type (standard, PO box, unique) or a neighbourhood for each ZIP.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

Cities and towns in Dewey County

A further 4 places in Dewey 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 Dewey County

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

605 Area code 605

Where Dewey County's ZIP codes sit

Each point is the reference point of one Dewey 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 Dewey 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.