ZIP Code 81154 — South Fork, CO
81154 is a standard (street delivery) ZIP code serving South Fork, Colorado, in Rio Grande 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 81154 at a glance
| ZIP code | 81154 |
|---|---|
| Primary city | South Fork |
| State | Colorado (CO) |
| County | Rio Grande FIPS 08105 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Denver |
| Population | 1,363 |
| Coordinates | 37.634730, -106.671790 |
How ZIP+4 works in 81154
The four digits after the hyphen encode a delivery segment inside 81154. 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 81154 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 81154.
| ZIP | City | Distance |
|---|---|---|
| 81132 | Del Norte, CO | 15.4 mi |
| 81130 | Creede, CO | 21.2 mi |
| 81144 | Monte Vista, CO | 29.2 mi |
| 81147 | Pagosa Springs, CO | 32.9 mi |
| 81140 | La Jara, CO | 37.1 mi |
| 81149 | Saguache, CO | 37.1 mi |
| 81124 | Capulin, CO | 39.2 mi |
| 81120 | Antonito, CO | 40.5 mi |
Questions about 81154
What is the ZIP+4 code for 81154?
81154 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 81154, you need to look up a specific street address to get them.
What city is 81154?
81154 is assigned to South Fork, Colorado, in Rio Grande 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.