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Montana ZIP Codes
Jefferson County
Basin, MT
59631
59631 ZIP Code — Basin, MT
Jefferson County, Montana
ZIP code 59631 is located in
Basin ,
Montana ,
within Jefferson County .
It covers approximately 156.44 square miles and serves a population of
371 residents.
This is a standard ZIP code in the Mountain (MT) timezone,
served by area code 406 .
About ZIP code 59631
The housing stock consists of predominantly single-family detached homes. Most homes were built in the pre-1940, giving the area an established character. Median home value is $222,600. Owner-occupancy is high at 89%, well above the national average.
The gap between median ($49,375) and mean household income suggests income inequality — a small number of higher earners pull the average up. 46% of households receive Social Security income, suggesting a notable retiree or disability population.
The dominant occupation class is management, business, and professional, with construction as the leading industry. An above-average commute of 41 minutes suggests many residents work outside the immediate area.
Educational attainment is near the national average, with 31% of residents holding a bachelor's degree or higher.
Overall, ZIP code 59631 reflects a community defined by high homeownership and a significant Social Security-dependent population.
59631 ZIP code map
View map of 59631
Cities in ZIP code 59631
Below are the cities the US Postal Service accepts for ZIP code 59631. Using any city not on this list may result in mail delivery delays.
City
Status
Basin
Acceptable
Demographics
updated 06/2026
Population
Total population
371
Population density
2 / sq mi
State FIPS
30
County FIPS
043
Geography
Land area
156.44 sq mi
Water area
0.02 sq mi
Latitude
46.2574
Longitude
-112.3691
Timezone
Mountain (MT)
Area code
406
Economics
updated 06/2026
Household income
Income range
This ZIP
County avg
State avg
Under $50k
50.4%
34.6%
44.2%
$50k – $100k
17.9%
33.8%
32.0%
$100k – $200k
31.7%
28.5%
19.2%
Over $200k
0.0%
3.2%
4.7%
Demographics & statistics
$49,375
Median household income
$222,600
Median home value
31.4%
Bachelor's or higher
Age distribution
Age summary
Group Count % Under 18 47 12.7% 18 and over 324 87.3% 65 and over 97 26.1% Median age 54.7 years
Race & ethnicity
Black or African American
1.1%
Group Count % White 346 93.3% Asian 21 5.7% Black or African American 4 1.1%
Household income
Income range
This ZIP
County avg
State avg
Under $50k
50.4%
34.6%
44.2%
$50k – $100k
17.9%
33.8%
32.0%
$100k – $200k
31.7%
28.5%
19.2%
Over $200k
0.0%
3.2%
4.7%
Range % of households Under $10k 4.2% $15k–$25k 3.6% $25k–$35k 25.5% $35k–$50k 18.2% $50k–$75k 9.1% $75k–$100k 10.9% $100k–$150k 7.3% $150k–$200k 18.8% $200k+ 2.4% Median income $49,375
Housing
Housing overview
Metric Value Median home value $222,600 Median rent / month $0 Owner occupied 89.1% Renter occupied 10.9% Vacant 14.5% Single-family detached 93.3% Large apartment buildings 0.0% Mobile homes 6.7% Median rooms 5.5 Avg household size (owned) 2.07
Year built
Era % 2020 or later 0.0% 2010–2019 4.7% 2000–2009 15.5% 1990–1999 17.6% 1980–1989 4.1% 1970–1979 8.8% 1960–1969 11.4% 1950–1959 2.6% 1940–1949 2.6% 1939 or earlier 32.6%
Bedrooms
Size % of units No bedroom (studio) 6.7% 1 bedroom 11.9% 2 bedrooms 33.2% 3 bedrooms 8.8% 4 bedrooms 15.0% 5+ bedrooms 24.4%
Vehicles per household
Vehicles % of households No vehicle 0.6% 1 vehicle 3.6% 2 vehicles 33.3% 3 or more 62.4%
Heating fuel
Fuel type % Utility gas 3.0% Electricity 9.7% Propane / LP gas 52.7% Wood 31.5%
Households & families
Household type Count % Married-couple family 96 58.2% Cohabiting couple 0 0.0% Male householder, no spouse 48 29.1% Female householder, no spouse 21 12.7% Households with children under 18 24 14.5% Households with seniors (65+) 73 44.2% Average household size 2.25
Marital status
Status Male Female Never married 28.0% 0.0% Married 54.5% 77.4% Separated 2.8% 0.0% Widowed 0.0% 0.8% Divorced 14.7% 21.8%
Education
Some college, no degree
14.5%
Graduate / professional
11.3%
Metric % HS diploma or higher 91.9% Bachelor's or higher 31.4%
School enrollment (ages 3–17)
Type Count % Nursery / preschool 0 0.0% Kindergarten 1 1.5% Elementary school 34 51.5% High school 5 7.6% College / grad school 26 39.4%
Employment
Industry of employment
Professional & management
29.2%
Education & healthcare
13.3%
Arts, food & hospitality
7.2%
Public administration
5.6%
Agriculture & mining
3.1%
Finance & real estate
1.0%
Occupation
Category % Management, business & arts 57.9% Service 8.2% Sales & office 7.7% Natural resources & construction 8.2% Production & transportation 17.9%
Employment type
Type % Private sector 80.0% Government 14.9% Self-employed 5.1% Unpaid family workers 0.0%
Commute
Method % Drive alone 81.3% Carpool 4.8% Public transit 3.2% Walk 2.7% Work from home 5.3% Other means 2.7% Avg commute (minutes) 41.1
Poverty
Married-couple families
0.0%
Female-led households
0.0%
Income support
Source % of households Social Security 46.1% Retirement income 29.7% Supplemental Security 4.8% Cash public assistance 0.0% Food stamps / SNAP 0.6%
Health indicators
Condition % Obesity 31.3% High blood pressure 28.7% High cholesterol 31.3% Diabetes 9.6% Heart disease 6.0% Stroke 2.9% Asthma 10.1% Arthritis 25.0% Kidney disease 2.7% Pulmonary disease 6.8% Cancer 6.4%
Behavior / access % Smoking 19.7% Binge drinking 22.9% No physical activity 20.4% Less than 7 hrs sleep 31.4% Depression 22.3% Fair or poor health 13.0% Poor mental health 13.0% Poor physical health 10.8% No health insurance 11.7% Visited doctor (checkup) 68.9% Visited dentist 61.9% Cholesterol screening 88.7% Teeth loss 12.6%
Veterans & disability
Veterans Count % Civilian veterans 31 9.6%
Disability % Any disability 17.3% Under 18 31.9% 18–64 years 8.4% 65 and over 30.9%
Health insurance coverage
Type % Private insurance 67.7% Public insurance 53.9% No insurance 0.3% Uninsured under 19 0.0%
Language & origin
Language spoken at home (age 5+)
Language Count % English only 370 99.7% Spanish 16 4.3% Other Indo-European 0 0.0% Asian & Pacific Islander 0 0.0% Other languages 16 4.3%
Place of birth & citizenship
Origin Count % Native born (US) 350 94.3% Born in same state 350 94.3% Born in different state 143 38.5% Foreign born 0 0.0% Naturalized citizen 21 5.7% Not a US citizen 21 100.0%
Ancestry
Ancestry Count % Italian 117 31.5% French 60 16.2% Polish 12 3.2%
Ancestry Count % English 6 1.6% Dutch 6 1.6%
Technology access
Metric % of households Computer access 44.5% Internet access 100.0%
Source: U.S. Census Bureau, American Community Survey 2025 estimates.
Frequently asked questions about ZIP code 59631
What city is ZIP code 59631 in?
ZIP code 59631 is primarily assigned to Basin, Montana.
What county is ZIP code 59631 in?
ZIP code 59631 falls within Jefferson County, Montana.
Does ZIP code 59631 have an older population?
26% of residents in ZIP code 59631 are 65 or older, above the national average of ~17%.
Is ZIP code 59631 mostly owner-occupied?
89% of occupied units in ZIP code 59631 are owner-occupied, well above the national average.
Does ZIP code 59631 have a large retiree population?
46% of households in ZIP code 59631 receive Social Security income, suggesting a significant retiree or disability population.
Does ZIP code 59631 have a large veteran population?
10% of civilians in ZIP code 59631 are veterans, above the national average of ~7%.
What timezone is ZIP code 59631 in?
ZIP code 59631 observes the MST timezone.
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