ZIP Code 91759 — Mt Baldy, CA
91759 is a standard (street delivery) ZIP code serving Mt Baldy, California, in Los Angeles 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 91759 at a glance
| ZIP code | 91759 |
|---|---|
| Primary city | Mt Baldy |
| State | California (CA) |
| County | Los Angeles FIPS 06037 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Los_Angeles |
| Population | 341 |
| Coordinates | 34.254100, -117.691940 |
How ZIP+4 works in 91759
The four digits after the hyphen encode a delivery segment inside 91759. 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 91759 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 91759.
| ZIP | City | Distance |
|---|---|---|
| 92358 | Lytle Creek, CA | 7.1 mi |
| 92397 | Wrightwood, CA | 7.5 mi |
| 91702 | Azusa, CA | 7.7 mi |
| 91784 | Upland, CA | 8 mi |
| 91750 | La Verne, CA | 8.4 mi |
| 91711 | Claremont, CA | 8.8 mi |
| 91737 | Rancho Cucamonga, CA | 9.4 mi |
| 91701 | Rancho Cucamonga, CA | 9.6 mi |
| 91741 | Glendora, CA | 10.1 mi |
| 91786 | Upland, CA | 10.4 mi |
| 91739 | Rancho Cucamonga, CA | 11.9 mi |
| 91773 | San Dimas, CA | 12.1 mi |
Questions about 91759
What is the ZIP+4 code for 91759?
91759 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 91759, you need to look up a specific street address to get them.
What city is 91759?
91759 is assigned to Mt Baldy, California, in Los Angeles 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.