County ZIP codes · Montana · FIPS 30029
Flathead County, MT ZIP Codes
Flathead County, Montana has 19 ZIP codes (Census 2020 ZCTA-county file; GeoNames postal codes, October 2026): 16 residential and 3 for PO boxes or a single organization. 14 of the residential ones lie mainly in Flathead County and 2 mainly in a neighboring county; 3 cross the county line. Median household income ranges from $31,970 in 59845 (Hot Springs) to $86,605 in 59920 (Kila) (Census Bureau, ACS 2020-2024).
- ACS2020-24
- Census2020
Where are the ZIP codes of Flathead County?
Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries; ACS 2020-2024 5-year estimates (B19013).
How different are its ZIP codes?
The middle half of its ranked ZIP codes (1,000+ people living in households) report median household incomes between $60,152 and $76,617.
They carry 16 postal town names.
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B19013).
All 16 residential ZIP codes in Flathead County
14 ZIP codes lie mainly in Flathead County; 2 more reach into it from a neighboring county and follow the first table.
| In this county | ||||||
|---|---|---|---|---|---|---|
| 59901 | Kalispell | 63,161 | 135 | $73k | $476k | 100% |
| 59912 | Columbia Falls | 15,752 | 83 | $77k | $489k | 100% |
| 59937 | Whitefish | 15,114 | 49 | $75k | $698k | 100% |
| 59922 | Lakeside | 2,337 | 61 | $87k | $658k | 90% |
| 59932 | Somers | 1,850 | 68 | $60k | $769k | 100% |
| 59920 | Kila | 1,704 | 9 | $87k | $723k | 100% |
| 59925 | Marion | 1,532 | 4 | $64k | $438k | 100% |
| 59936 | West Glacier | 690 | 0 | $86k | $532k | 100% |
| 59919 | Hungry Horse | 679 | 299 | $53k | – | 100% |
| 59913 | Coram | 582 | 11 | $45k | $560k | 100% |
| 59927 | Olney | 270 | 1 | $59k | $446k | 100% |
| 59926 | Martin City | 268 | 27 | $71k | $480k | 100% |
| 59916 | Essex | 232 | 2 | $60k | $390k | 100% |
| 59928 | Polebridge | 86 | 0 | $63k | $762k | 100% |
Partly in Flathead 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?
3 ZIP codes of Flathead County extend into another county. A ZIP code follows mail routes, not county borders.
| ZIP | In Flathead | Elsewhere |
|---|---|---|
| 59911 | 14% | Lake County 86% |
| 59922 | 90% | Lake County 10% |
| 59845 | 16% | Sanders County 67%; Lake County 17% |
Source: U.S. Census Bureau, 2020 ZCTA-county relationship file (shares of land area).
PO Box and single-organization ZIP codes
Source: GeoNames postal codes (CC BY 4.0).
Which first three digits do Flathead County's ZIP codes use?
The first three digits of a ZIP code name the sectional center, the mail processing plant that sorts it. Flathead County's ZIP codes use 2 prefixes: 598 and 599.
Source: U.S. Postal Service, labeling list L005 (3-digit ZIP Code prefix groups, SCF sortation), effective October 1, 2026.