County ZIP codes · Montana · FIPS 30103
Treasure County, MT ZIP Codes
Treasure County, Montana has 3 ZIP codes (Census 2020 ZCTA-county file; GeoNames postal codes, October 2026), all residential. 2 of the residential ones extend into a neighboring county.
- ACS2020-24
- Census2020
Where are the ZIP codes of Treasure County?
Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries; ACS 2020-2024 5-year estimates (B19013).
All 3 residential ZIP codes in Treasure County
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates; county shares by land area (Census 2020 ZCTA-county relationship file).
Which ZIP codes cross the county line?
2 ZIP codes of Treasure County extend into another county. A ZIP code follows mail routes, not county borders.
| ZIP | In Treasure | Elsewhere |
|---|---|---|
| 59038 | 87% | Big Horn County13% |
| 59010 | 55% | Big Horn County45% |
Source: U.S. Census Bureau, 2020 ZCTA-county relationship file (shares of land area).
Which first three digits do Treasure County's ZIP codes use?
The first three digits of a ZIP code name the sectional center, the mail processing plant that sorts it. Every ZIP code of Treasure County starts with 590.
| Prefix | Sectional center | Here | All codes |
|---|---|---|---|
| 590 | Billings, MT (SCF 590) | 3 | 75 |
Source: U.S. Postal Service, labeling list L005 (3-digit ZIP Code prefix groups, SCF sortation), effective October 1, 2026.