| Locality | Post Code |
|---|---|
| Alexandria, Clark | 63430 |
| Ashton, Clark | 63453 |
| Athens, Clark | 63465 |
| Fairmont, Clark | 63474 |
| Kahoka, Clark | 63445 |
| Luray, Clark | 63453 |
| Medill, Clark | 63445 |
| Peaksville, Clark | 63465 |
| Revere, Clark | 63465 |
| Saint Francisville, Clark | 63430 |
| Saint Patrick, Clark | 63466 |
| Wayland, Clark | 63472 |
| Wyaconda, Clark | 63474 |