First three digits · Montana
ZIP Codes Starting with
30 ZIP codes start with 599, sorted at the Missoula, MT (SCF 598) sectional center (USPS labeling list L005, effective October 1, 2026) in Montana: 27 residential ZIP codes across 3 counties and 3 PO Box or single-organization codes (Census 2020 ZCTAs and GeoNames postal codes, October 2026).
What do the digits 599 mean?
The first digit, 5, is one of ten national areas (Iowa, Minnesota, Montana, North Dakota, South Dakota and Wisconsin). The first three, 599, route mail to a sectional center: USPS labeling list L005 (effective October 1, 2026) sends letters for 599 to the Missoula, MT (SCF 598) facility. The last two digits pick the delivery area. By residents, the largest town names among the 599 ZIP codes are Kalispell, Columbia Falls, Whitefish, Libby, Bigfork and Eureka.
The same facility sorts 2 prefixes, 83 ZIP codes in all: 598, 599.
Where are the 599 ZIP codes?
Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries; ACS 2020-2024 5-year estimates (B19013).
All ZIP codes starting with 599
| County | ||||||
|---|---|---|---|---|---|---|
| 59901 | Kalispell | Flathead County | 63,161 | 135 | $73k | $476k |
| 59903 | Kalispell | Flathead County | PO Box or unique | – | – | – |
| 59904 | Kalispell | Flathead County | PO Box or unique | – | – | – |
| 59910 | Big Arm | Lake County | 692 | 36 | $100k | $589k |
| 59911 | Bigfork | Lake County | 9,493 | 19 | $83k | $666k |
| 59912 | Columbia Falls | Flathead County | 15,752 | 83 | $77k | $489k |
| 59913 | Coram | Flathead County | 582 | 11 | $45k | $560k |
| 59914 | Dayton | Lake County | 345 | 31 | $84k | $1.21M |
| 59915 | Elmo | Lake County | 452 | 8 | $59k | – |
| 59916 | Essex | Flathead County | 232 | 2 | $60k | $390k |
| 59917 | Eureka | Lincoln County | 4,920 | 20 | $50k | $360k |
| 59918 | Fortine | Lincoln County | 509 | 5 | $67k | $353k |
| 59919 | Hungry Horse | Flathead County | 679 | 299 | $53k | – |
| 59920 | Kila | Flathead County | 1,704 | 9 | $87k | $723k |
| 59921 | Lake McDonald | Flathead County | PO Box or unique | – | – | – |
| 59922 | Lakeside | Flathead County | 2,337 | 61 | $87k | $658k |
| 59923 | Libby | Lincoln County | 10,450 | 7 | $45k | $272k |
| 59925 | Marion | Flathead County | 1,532 | 4 | $64k | $438k |
| 59926 | Martin City | Flathead County | 268 | 27 | $71k | $480k |
| 59927 | Olney | Flathead County | 270 | 1 | $59k | $446k |
| 59928 | Polebridge | Flathead County | 86 | 0 | $63k | $762k |
| 59929 | Proctor | Lake County | 230 | 6 | $101k | – |
| 59930 | Rexford | Lincoln County | 1,220 | 13 | $62k | $287k |
| 59931 | Rollins | Lake County | 335 | 12 | $112k | $743k |
| 59932 | Somers | Flathead County | 1,850 | 68 | $60k | $769k |
| 59933 | Stryker | Lincoln County | 2 | 0 | – | – |
| 59934 | Trego | Lincoln County | 693 | 6 | $109k | $331k |
| 59935 | Troy | Lincoln County | 3,381 | 3 | $40k | $371k |
| 59936 | West Glacier | Flathead County | 690 | 0 | $86k | $532k |
| 59937 | Whitefish | Flathead County | 15,114 | 49 | $75k | $698k |
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates; GeoNames postal codes (CC BY 4.0) for codes without a residential area.