ZIP Codes of Carter County, MT

Population & People
Population & People
Total Population
1,115
Household Income
Household Income
Median Income
$56,550
Housing
Housing
Total Housing Units
748
Business & Economy
Business & Economy
Total Businesses
21
Employment
Employment
Employment Rate
54.78%
Education
Education
Bachelor's Degree+
20.85%
Source: U.S. Census ACS 2024 5-Year Estimates · rolled up across the 5 ZIPs in this county.
Data Last Updated: June 1, 2026
ZIP Codes:5 ZIP Codes (5 Standard, 0 PO Box, 0 Unique) [See All]
Area Code:406
Timezone:Mountain (GMT -07:00)
Local Time:2:12:52 PM
Population:1,115 [See All]
FIPS:30011
Land Area:3,217 sq mi
Water Area:4 sq mi
Coordinates:45.4508, -104.5590
Quick Link:
https://www.zip-codes.com/county/mt-carter.asp
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Notable income spread
Median income ranges $32,241 to $88,021 across ZIPs — a 2.7× gap.
Among Montana's 5 oldest counties
Median age 57.9.

Standout ZIPs in this County


Most Populous
Ekalaka · 777 people
69.7% of county total
Highest Income
Alzada · $88,021 median
1.6× county average
Largest Land Area
Ekalaka · 1,213.9 sq mi
Spans the most ground
Fastest Growth
— growth not calculable
Most Educated
— no education data

Things worth knowing about Carter County


1,115 residents live across 5 ZIPs covering 3,217 sq mi, served by 5 distinct USPS-recognized cities.

Population moved from 1,169 to 1,060 from 2014 to 2024 — a -9.3% change. 0 ZIPs gained residents, 3 lost.

The county's wealthiest ZIP 59311 (Alzada, $88,021 median) and poorest ZIP 59332 (Hammond, $32,241) are 23.7 miles apart — a 2.7× income gap across local geography.

Density varies across the county — from 0 people/sq mi in 59311 (Alzada) to 1 in 59324 (Ekalaka).

Educational attainment ranges from 14.0% bachelor's+ in 59311 (Alzada) to 35.7% in 59332 (Hammond) — the breadth of educational profiles across the area.

Within Montana, this is the #52 most populous of 56 counties and ranks #48 for median household income .

Weighted by population, the typical household earns about $57,923 across the county — reflecting what a typical resident sees, not a simple ZIP average.

20.9% of adults age 25+ hold a bachelor's degree or higher (181 of 868 reporting).

5 Standard delivery, 0 PO Box only, 0 single-entity Unique ZIPs serve this county.

Stories about Carter County


Big & sparse

A frontier county — vast land area with only a few residents per square mile. Daily life looks very different here than in the country's denser counties.

Total area
3,217
square miles
Avg density
0.3
people per sq mi
Population
1,115
across 5 ZIPs
Ekalaka
1,213.9 sq mi
777 residents
Alzada
950.0 sq mi
143 residents
Hammond
604.4 sq mi
140 residents

Single-ZIP anchor

One ZIP holds the majority of this county's population — a sign of a county built around a single city or town.

Ekalaka

All ZIP Codes in Carter County


ZIPCityTypePopulationMedian IncomeArea (sq mi)10-yr Growth
59324EkalakaStandard777$57,1881,213.9-8.9%
59311AlzadaStandard143$88,021950.0-16.9%
59332HammondStandard140$32,241604.4-2.8%
59319CapitolStandard40309.1
59316BoyesStandard15$48,750140.0

Adjacent & Nearby Counties