| Official Zip Code Name | Big Arm |
| Zip Code State | Montana |
| Primary County: | Lake |
| Area Code | 406 |
| Current Population: | 37081 |
| Racial Majority: | White 62.49% |
| Median Household Income | $55618 |
| Average Adjusted Gross Income | $89060 |
| Time Zone: | 7 |
| Elevation Range | 3065 ft. |
| Area | 19.251 Sqm. |
| Coordinates(Y,X) | 47.785369, -114.298867 |