ZIP codes in Broadwater County
7 ZIPs touch Broadwater County, Montana. The blue dashed line is the county border; orange ZIPs reach into it.
7
ZIP codes
3
cross the county line
20,719
people in these ZIPs
56
counties in MT
Most people
Broadwater County ZIP list
More counties in Montana
- Beaverhead County10
- Big Horn County17
- Blaine County10
- Carbon County13
- Carter County8
- Cascade County21
- Chouteau County13
- Custer County7
- Daniels County5
Questions people actually ask
How many ZIP codes are in Broadwater County, Montana?
7 ZIP codes reach into Broadwater County, including 1 PO Box or single-address ZIPs placed by the town they serve. 3 of them are only partly in the county and also cover a neighboring county.
Which ZIP code in Broadwater County has the most people?
59635 (East Helena) has about 8,292 residents, the most of any ZIP touching Broadwater County, in the Census Bureau’s ACS 2020–2024 estimates.
Can a ZIP code be in Broadwater County and another county?
Yes. ZIP codes follow mail routes, not county lines. Rows marked with a percentage show how much of that ZIP’s land is in Broadwater County. For one address, pin the exact spot on the ZIP finder to see its county.
Where does this list come from?
ZIP areas and their county overlaps come from the Census Bureau’s 2020 ZIP Code Tabulation Area to county relationship file. PO Box ZIPs have no area, so each is placed in the county of the ZIP area nearest the town it serves.
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Updated 2026-11-10 · Where the data comes from