ZIP Code 57339 — Fort Thompson, SD
57339 is a standard (street delivery) ZIP code serving Fort Thompson, South Dakota, in Buffalo County. To mail something here you only need these five digits — but the four-digit extension narrows delivery to a single point, and it is what USPS bulk postage discounts are priced on.
ZIP code 57339 at a glance
| ZIP code | 57339 |
|---|---|
| Primary city | Fort Thompson |
| State | South Dakota (SD) |
| County | Buffalo FIPS 46017 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 1,390 |
| Coordinates | 44.112330, -99.478620 |
How ZIP+4 works in 57339
The four digits after the hyphen encode a delivery segment inside 57339. In practice one segment usually means:
- One side of one block — odd numbers on a street between two cross streets
- A single large building, or one floor of it
- A group of PO boxes, sometimes a single box
- A single business that receives enough mail to warrant its own code
That is why 57339 has no single ZIP+4: two neighbors across the street from each other usually have different ones. Enter a street address above and we will return the exact nine-digit code along with the standardized USPS address format.
Nearby ZIP codes
Showing the closest twelve. See every ZIP code within 25 miles of 57339.
| ZIP | City | Distance |
|---|---|---|
| 57548 | Lower Brule, SD | 7.4 mi |
| 57346 | Stephan, SD | 9.4 mi |
| 57569 | Reliance, SD | 18 mi |
| 57341 | Gann Valley, SD | 19.4 mi |
| 57325 | Chamberlain, SD | 20.6 mi |
| 57365 | Oacoma, SD | 21 mi |
| 57544 | Kennebec, SD | 23.7 mi |
| 57540 | Holabird, SD | 25.1 mi |
| 57371 | Ree Heights, SD | 25.2 mi |
| 57536 | Harrold, SD | 25.3 mi |
| 57370 | Pukwana, SD | 26.1 mi |
| 57345 | Highmore, SD | 31.5 mi |
Questions about 57339
What is the ZIP+4 code for 57339?
57339 is the five-digit ZIP code. The ZIP+4 adds four more digits that identify a specific delivery point — usually one side of a city block, a single building, or a group of PO boxes. Because those four digits change from address to address within 57339, you need to look up a specific street address to get them.
What city is 57339?
57339 is assigned to Fort Thompson, South Dakota, in Buffalo County.
Do I need to use the ZIP+4?
It is optional for ordinary mail, but it speeds up sorting and it is required for most USPS bulk-mail postage discounts. Many address-verification and e-commerce systems also use ZIP+4 to confirm a delivery point exists.
Need thousands of these?
Upload a CSV and get ZIP+4, county, carrier route, and delivery-point data appended to every row — or call the API directly.