ZIP Code 57750 — Interior, SD
57750 is a standard (street delivery) ZIP code serving Interior, South Dakota, in Jackson 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 57750 at a glance
| ZIP code | 57750 |
|---|---|
| Primary city | Interior |
| State | South Dakota (SD) |
| County | Jackson FIPS 46071 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Denver |
| Population | 365 |
| Coordinates | 43.601090, -101.948580 |
How ZIP+4 works in 57750
The four digits after the hyphen encode a delivery segment inside 57750. 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 57750 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 57750.
| ZIP | City | Distance |
|---|---|---|
| 57577 | Wanblee, SD | 15.4 mi |
| 57752 | Kyle, SD | 17.2 mi |
| 57714 | Allen, SD | 19 mi |
| 57543 | Kadoka, SD | 23.6 mi |
| 57547 | Long Valley, SD | 26.7 mi |
| 57780 | Scenic, SD | 28.2 mi |
| 57772 | Porcupine, SD | 29.7 mi |
| 57551 | Martin, SD | 31.5 mi |
| 57775 | Quinn, SD | 33.4 mi |
| 57756 | Manderson, SD | 36.4 mi |
| 57794 | Wounded Knee, SD | 40.3 mi |
| 57574 | Tuthill, SD | 44.8 mi |
Questions about 57750
What is the ZIP+4 code for 57750?
57750 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 57750, you need to look up a specific street address to get them.
What city is 57750?
57750 is assigned to Interior, South Dakota, in Jackson 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.