| Locality | Post Code |
|---|---|
| Orleans, Humboldt | 95556 |
| Petrolia, Humboldt | 95558 |
| Phillipsville, Humboldt | 95559 |
| Redcrest, Humboldt | 95569 |
| Redway, Humboldt | 95560 |
| Resighini Rancheria, Humboldt | 95546 |
| Rio Dell, Humboldt | 95562 |
| Ruth, Humboldt | 95526 |
| Samoa, Humboldt | 95564 |
| Scotia, Humboldt | 95565 |
| Shelter Cove, Humboldt | 95589 |
| Trinidad, Humboldt | 95570 |
| Weitchpec, Humboldt | 95546 |
| Weott, Humboldt | 95571 |
| Whitethorn, Humboldt | 95589 |
| Willow Creek, Humboldt | 95573 |