ZIP Code 57645 — Morristown, SD
57645 is a standard (street delivery) ZIP code serving Morristown, South Dakota, in Corson 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 57645 at a glance
| ZIP code | 57645 |
|---|---|
| Primary city | Morristown |
| State | South Dakota (SD) |
| County | Corson FIPS 46031 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Denver |
| Population | 184 |
| Coordinates | 45.911900, -101.718550 |
How ZIP+4 works in 57645
The four digits after the hyphen encode a delivery segment inside 57645. 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 57645 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 57645.
| ZIP | City | Distance |
|---|---|---|
| 57660 | Watauga, SD | 10.5 mi |
| 57634 | Keldron, SD | 13.4 mi |
| 57641 | Mcintosh, SD | 19.8 mi |
| 57638 | Lemmon, SD | 23.7 mi |
| 58529 | Carson, ND | 27.8 mi |
| 58564 | Raleigh, ND | 30 mi |
| 58533 | Elgin, ND | 33.5 mi |
| 57633 | Isabel, SD | 33.8 mi |
| 58562 | New Leipzig, ND | 34.2 mi |
| 58569 | Shields, ND | 34.7 mi |
| 57644 | Meadow, SD | 36.2 mi |
| 58646 | Mott, ND | 43.3 mi |
Questions about 57645
What is the ZIP+4 code for 57645?
57645 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 57645, you need to look up a specific street address to get them.
What city is 57645?
57645 is assigned to Morristown, South Dakota, in Corson 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.