Sully County ZIP Codes
Sully County is a county of South Dakota.
- ZIP codes
- 2
- Cities & towns
- 2
- Area codes
- 1
- Land area
- 1,007 sq mi
Every ZIP code in Sully County
| ZIP code | City |
|---|---|
| 57520 | Agar |
| 57564 | Onida |
We do not publish a delivery type (standard, PO box, unique) or a neighbourhood for each ZIP.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 Sully County codes above are listed without a column we would have to invent.
Cities and towns in Sully County
Area codes covering Sully County
Telephone and postal boundaries are drawn by different bodies, so these codes overlap the county without matching its edges.
Scope every ZIP code recorded in Sully 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 . The outline is a convex envelope of ZIP reference points, not a jurisdiction boundary.