| Locality | Post Code |
|---|---|
| Busby, Big Horn | 59016 |
| Crow Agency, Big Horn | 59022 |
| Decker, Big Horn | 59025 |
| Fort Smith, Big Horn | 59035 |
| Garryowen, Big Horn | 59031 |
| Hardin, Big Horn | 59034 |
| Kirby, Big Horn | 59016 |
| Lodge Grass, Big Horn | 59050 |
| Pryor, Big Horn | 59066 |
| Saint Xavier, Big Horn | 59075 |
| Wyola, Big Horn | 59089 |
| Yellowtail, Big Horn | 59035 |