| ZIP | County | State | Area Code | Time Zone |
| 59601 | Lewis and Clark | MT | 406 | MST |
| 59602 | Lewis and Clark | MT | 406 | MST |
| 59604 | Lewis and Clark | MT | 406 | MST |
| 59620 | Lewis and Clark | MT | 406 | MST |
| 59623 | Lewis and Clark | MT | 406 | MST |
| 59624 | Lewis and Clark | MT | 406 | MST |
| 59625 | Lewis and Clark | MT | 406 | MST |
| 59626 | Lewis and Clark | MT | 406 | MST |