7 zips
| Zip Code | City | Population ↓ |
|---|---|---|
| 97850 | La Grande | 16,545 |
| 97883 | Union | 2,634 |
| 97827 | Elgin | 2,557 |
| 97824 | Cove | 1,923 |
| 97876 | Summerville | 1,092 |
| 97867 | North Powder | 1,057 |
| 97841 | Imbler | 428 |
The data shown reflect ZCTAs from the US Census. As of 2024, there are 7 ZCTAs in Union County, Oregon (US Census).