| Locality | Postal Code |
|---|---|
| Augusta, Lewis And Clark | 59410 |
| Canyon Creek, Lewis And Clark | 59633 |
| Craig, Lewis And Clark | 59648 |
| East Helena, Lewis And Clark | 59635 |
| Fort Harrison, Lewis And Clark | 59636 |
| Helena, Lewis And Clark | 59601, 59602, 59625, 59626 |
| Lincoln, Lewis And Clark | 59639 |
| Marysville, Lewis And Clark | 59640 |
| Wolf Creek, Lewis And Clark | 59648 |