| Zip Code | City | Population ↓ |
|---|---|---|
| 57252 | Milbank | 4,669 |
| 57216 | Big Stone City | 1,584 |
| 57259 | Revillo | 605 |
| 57266 | Summit | 571 |
| 57264 | Stockholm | 252 |
| 57256 | Ortley | 223 |
| 57265 | Strandburg | 204 |
| 57251 | Marvin | 191 |
| 57269 | Twin Brooks | 179 |
| 57246 | Labolt | 145 |
The data shown reflect ZCTAs from the US Census. As of 2024, there are 10 ZCTAs in Grant County, South Dakota (US Census).