ZIP Code 82604 — Casper, WY
82604 is a standard (street delivery) ZIP code serving Casper, Wyoming, in Natrona 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 82604 at a glance
| ZIP code | 82604 |
|---|---|
| Primary city | Casper |
| State | Wyoming (WY) |
| County | Natrona FIPS 56025 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Denver |
| Population | 27,487 |
| Coordinates | 42.917510, -106.708400 |
How ZIP+4 works in 82604
The four digits after the hyphen encode a delivery segment inside 82604. 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 82604 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.
Other ZIP codes in Casper
Nearby ZIP codes
Showing the closest twelve. See every ZIP code within 25 miles of 82604.
| ZIP | City | Distance |
|---|---|---|
| 82646 | Natrona, WY | 5.4 mi |
| 82644 | Mills, WY | 17.6 mi |
| 82601 | Casper, WY | 21 mi |
| 82648 | Powder River, WY | 23.1 mi |
| 82609 | Casper, WY | 27.9 mi |
| 82636 | Evansville, WY | 29.1 mi |
| 82638 | Hiland, WY | 29.5 mi |
| 82620 | Alcova, WY | 33 mi |
| 82630 | Arminto, WY | 39.9 mi |
Questions about 82604
What is the ZIP+4 code for 82604?
82604 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 82604, you need to look up a specific street address to get them.
What city is 82604?
82604 is assigned to Casper, Wyoming, in Natrona 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.