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County ZIP codes · Montana · FIPS 30017

Custer County, MT ZIP Codes

Custer County, Montana has 7 ZIP codes (Census 2020 ZCTA-county file; GeoNames postal codes, October 2026), all residential. 4 of the residential ones lie mainly in Custer County and 3 mainly in a neighboring county; 6 cross the county line.

  • ACS2020-24
  • Census2020

Where are the ZIP codes of Custer County?

59301 · Miles City: $71k59336 · Ismay: $64k59338 · Kinsey: $69k59345 · Powderville: $68k59347 · Rosebud: $57k59349 · Terry: $63k59351 · Volborg: –5930159349593365934759351593455933859301 · Miles City: $71k59336 · Ismay: $64k59338 · Kinsey: $69k59345 · Powderville: $68k59347 · Rosebud: $57k59349 · Terry: $63k59351 · Volborg: –5930159349593365934759351593455933859301 · Miles City: $71k59336 · Ismay: $64k59338 · Kinsey: $69k59345 · Powderville: $68k59347 · Rosebud: $57k59349 · Terry: $63k59351 · Volborg: –593015934959336593475935159345
The residential ZIP codes of Custer County (whole outlines, including the parts in neighboring counties), shaded by median household income in national fifths (ACS 2020-2024).<$54.1k$98.1k+no figure

Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries; ACS 2020-2024 5-year estimates (B19013).

All 7 residential ZIP codes in Custer County

4 ZIP codes lie mainly in Custer County; 3 more reach into it from a neighboring county and follow the first table.

Residential ZIP codes mainly in Custer County, largest first; "In this county" is the share of the ZIP's land in the county
In this county
59301 Miles City 11,643 4 $71k $218k 81%
59336 Ismay 220 0 $64k $293k 65%
59338 Kinsey 136 2 $69k $337k 100%
59345 Powderville 35 0 $68k $225k 68%

Partly in Custer County

Residential ZIP codes mainly in another county that reach at least 1% into Custer County, by their share here
In this county
59351 Volborg 202 0 – $118k 40%
59347 Rosebud 323 0 $57k $68k 8%
59349 Terry 1,025 1 $63k $158k 1%

Download the 7 ZIP codes as CSV

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?

6 ZIP codes of Custer County extend into another county. A ZIP code follows mail routes, not county borders.

Share of each ZIP code's land in Custer County and in the neighboring counties
ZIPIn CusterElsewhere
5930181%Rosebud County10%; Garfield County5%; Powder River County2%; Prairie County1%
593491%Prairie County99%
593478%Rosebud County92%
5933665%Fallon County28%; Carter County6%
5935140%Powder River County60%
5934568%Powder River County32%

Source: U.S. Census Bureau, 2020 ZCTA-county relationship file (shares of land area).

Which first three digits do Custer 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 Custer County starts with 593.

Three-digit prefixes of Custer County's ZIP codes, the sectional center for each (USPS labeling list L005, effective October 1, 2026) and how many of the prefix's codes are Custer County's
PrefixSectional centerHereAll codes
593Billings, MT (SCF 590)731

Source: U.S. Postal Service, labeling list L005 (3-digit ZIP Code prefix groups, SCF sortation), effective October 1, 2026.