| Locality | Postal Code |
|---|---|
| Postal/ZIP Codes in Calion, Union | 71724 |
| Postal/ZIP Codes in El Dorado, Union | 71730 |
| Postal/ZIP Codes in Huttig, Union | 71747 |
| Postal/ZIP Codes in Junction City, Union | 71749 |
| Postal/ZIP Codes in Lawson, Union | 71750 |
| Postal/ZIP Codes in Mount Holly, Union | 71758 |
| Postal/ZIP Codes in Norphlet, Union | 71759 |
| Postal/ZIP Codes in Smackover, Union | 71762 |
| Postal/ZIP Codes in Strong, Union | 71765 |