Boulder ZIP Code List — Jefferson County, MT

There is one unique ZIP code in Boulder, Montana and it is 59632. Area code: 406.

ZIP codes

444.05

sq mi land

1.20

sq mi water

406

area code

Boulder, MT ZIP code map

About Boulder, MT

Boulder is a charming city located in Jefferson County, Montana. Known for its beautiful landscapes and friendly community, it offers a welcoming atmosphere to both residents and visitors. This quaint town serves as the county seat and boasts a rich history that contributes to its unique character.

Location & geography

Boulder is situated in the southwestern part of Montana, surrounded by stunning natural scenery. The city is approximately 28 miles from the capital, Helena, and about 50 miles from Butte, making it accessible to larger urban areas while still embracing its small-town charm. The city covers a land area of 444.05 square miles, with a water area of 1.20 square miles, providing ample space for outdoor activities and enjoying the beautiful terrain.

Community & economy

The community of Boulder is characterized by its friendly residents and a strong commitment to local traditions and events. The local economy is supported by various industries including agriculture and small businesses, fostering a close-knit, supportive community. Daily life in Boulder is often enriched by outdoor recreational opportunities, local festivals, and a deep appreciation for the region's history.

Transportation

Boulder is conveniently accessible via Interstate 15, which runs north to south through Montana and connects the city to larger metropolitan areas. The nearest major airport is Helena Regional Airport, located about 30 miles away, providing additional travel options for residents and visitors. Local transportation options are limited, but the community’s compact size makes it easy to navigate on foot or by bicycle.

History

Boulder was founded in the 1860s, with a significant boost from the gold rush that attracted miners and settlers to the area. The city's history is heavily influenced by its mining roots, which laid the foundation for its early economy and growth. Over the years, Boulder has evolved but has maintained its historical charm, with notable events such as the annual Jefferson County Fair showcasing its rich heritage.

Did you know?

One surprising fact about Boulder is that it is home to the Montana State Hospital, which has been operating since the late 1800s and is one of the oldest mental health facilities in the United States. Additionally, the city is located near the scenic Boulder Mountains, offering residents and visitors picturesque views and recreational activities.

ZIP codes for Boulder, MT (1)

ZIP code	City	County	Map
59632	Boulder	Jefferson	View map

Demographics & statistics

2,412

Population

43.7

Median age

$59,789

Median household income

$33,515

Per capita income

$245,300

Median home value

$743

Median monthly rent

74.6%

Home ownership

7.1%

Poverty rate

5.5%

Unemployment

814

Housing units

28.0%

Bachelor's or higher

Age distribution

Male Female

Under 5

5–9

10–14

15–19

116

20–24

106

25–34

200

35–44

161

212

45–54

172

135

55–59

109

108

60–64

123

65–74

100

75–84

← Male

Female →

Age summary

Group	Count	%
Under 18	486	20.1%
18 and over	1,926	79.9%
65 and over	293	12.1%
Median age	43.7 years

Race & ethnicity

White 86.5%

Two or more races 6.6%

Hispanic or Latino 2.8%

American Indian / Alaska Native 2.5%

Other race 0.9%

Asian 0.7%

Group	Count	%
White	2,145	86.5%
Two or more races	164	6.6%
Hispanic or Latino	69	2.8%
American Indian / Alaska Native	63	2.5%
Other race	22	0.9%
Asian	18	0.7%

Household income

Under $10k 4.0%

$15k–$25k 11.7%

$25k–$35k 4.7%

$35k–$50k 15.8%

$50k–$75k 25.3%

$75k–$100k 10.7%

$100k–$150k 14.2%

$150k–$200k 6.7%

$200k+ 7.0%

Range	% of households
Under $10k	4.0%
$15k–$25k	11.7%
$25k–$35k	4.7%
$35k–$50k	15.8%
$50k–$75k	25.3%
$75k–$100k	10.7%
$100k–$150k	14.2%
$150k–$200k	6.7%
$200k+	7.0%
Median income	$59,789

Housing

Home values

Under $50k 6.3%

$50k–$100k 10.8%

$100k–$150k 5.7%

$150k–$200k 13.2%

$200k–$300k 32.2%

$300k–$500k 20.5%

$500k–$1M 11.4%

Housing overview

Metric	Value
Median home value	$245,300
Median rent / month	$743
Owner occupied	74.6%
Renter occupied	25.4%
Vacant	12.4%
Single-family detached	76.5%
Large apartment buildings	2.0%
Mobile homes	18.1%
Median rooms	5.2
Avg household size (owned)	2.35

Year built

Era	%
2020 or later	1.7%
2010–2019	5.8%
2000–2009	19.0%
1990–1999	9.8%
1980–1989	7.7%
1970–1979	22.8%
1960–1969	4.8%
1950–1959	5.7%
1940–1949	3.0%
1939 or earlier	19.6%

Bedrooms

Size	% of units
No bedroom (studio)	0.9%
1 bedroom	17.5%
2 bedrooms	23.5%
3 bedrooms	45.4%
4 bedrooms	10.3%
5+ bedrooms	2.5%

Vehicles per household

Vehicles	% of households
No vehicle	3.6%
1 vehicle	17.3%
2 vehicles	38.5%
3 or more	40.6%

Heating fuel

Fuel type	%
Utility gas	39.4%
Electricity	6.9%
Propane / LP gas	25.2%
Wood	27.6%

Households & families

Household type	Count	%
Married-couple family	502	54.7%
Cohabiting couple	52	5.7%
Male householder, no spouse	203	22.1%
Female householder, no spouse	160	17.4%
Households with children under 18	267	29.1%
Households with seniors (65+)	222	24.2%
Average household size	2.41

Marital status

Status	Male	Female
Never married	33.6%	22.7%
Married	47.1%	55.2%
Separated	2.7%	2.0%
Widowed	0.7%	5.6%
Divorced	15.9%	14.5%

Education

Less than 9th grade 3.9%

Some HS, no diploma 3.8%

HS graduate 30.0%

Some college, no degree 27.9%

Associate's degree 6.5%

Bachelor's degree 23.5%

Graduate / professional 4.4%

Metric	%
HS diploma or higher	92.3%
Bachelor's or higher	28.0%

School enrollment (ages 3–17)

Type	Count	%
Nursery / preschool	39	8.1%
Kindergarten	13	2.7%
Elementary school	236	49.0%
High school	102	21.2%
College / grad school	92	19.1%

Employment

Industry of employment

Education & healthcare 27.0%

Construction 12.0%

Public administration 11.0%

Agriculture & mining 9.7%

Transportation & utilities 9.7%

Retail trade 9.4%

Arts, food & hospitality 7.4%

Professional & management 6.4%

Other services 3.8%

Manufacturing 3.6%

Occupation

Category	%
Management, business & arts	46.2%
Service	12.8%
Sales & office	10.7%
Natural resources & construction	18.5%
Production & transportation	11.8%

Employment type

Type	%
Private sector	72.0%
Government	24.8%
Self-employed	3.3%
Unpaid family workers	0.0%

Commute

Method	%
Drive alone	69.0%
Carpool	10.4%
Public transit	0.0%
Walk	3.9%
Other means	1.6%
Avg commute (minutes)	29.4

Poverty

All people 7.1%

Under 18 years 0.0%

18 and over 8.8%

Married-couple families 0.0%

Female-led households 0.0%

Income support

Source	% of households
Social Security	32.1%
Retirement income	28.6%
Supplemental Security	2.2%
Cash public assistance	7.9%
Food stamps / SNAP	9.5%

Health indicators

Condition	%
High blood pressure	28.5%
High cholesterol	31.3%
Heart disease	6.1%
Stroke	2.9%
Asthma	10.2%
Arthritis	25.1%
Kidney disease	2.8%
Pulmonary disease	6.8%
Cancer	6.6%

Behavior / access	%
Binge drinking	22.4%
No physical activity	20.6%
Less than 7 hrs sleep	30.8%
Fair or poor health	12.9%
Poor mental health	13.2%
Poor physical health	10.8%
No health insurance	11.8%
Visited doctor (checkup)	69.5%
Visited dentist	62.4%
Cholesterol screening	88.2%
Teeth loss	13.4%

Veterans & disability

Veterans	Count	%
Civilian veterans	329	17.1%

Disability	%
Any disability	15.3%
Under 18	0.0%
18–64 years	13.5%
65 and over	48.1%

Health insurance coverage

Type	%
Private insurance	62.6%
Public insurance	43.2%
Uninsured under 19	2.0%

Language & origin

Language spoken at home (age 5+)

Language	Count	%
English only	2,280	94.5%
Spanish	41	1.8%
Other Indo-European	23	1.0%
Asian & Pacific Islander	0	0.0%
Other languages	18	0.8%

Place of birth & citizenship

Origin	Count	%
Native born (US)	2,394	99.3%
Born in same state	2,391	99.1%
Born in different state	1,500	62.2%
Foreign born	3	0.1%
Naturalized citizen	18	0.7%
Not a US citizen	0	0.0%

Ancestry

Ancestry	Count	%
Italian	694	28.8%
French	294	12.2%
Polish	158	6.6%
Arab	92	3.8%

Ancestry	Count	%
German	41	1.7%
Irish	13	0.5%
Dutch	13	0.5%

Technology access

Metric	% of households
Computer access	38.0%
Internet access	97.9%

Source: U.S. Census Bureau, American Community Survey 2025 estimates.

Frequently asked questions

What is the ZIP code for Boulder, MT?

Boulder, MT has one ZIP code: 59632.

What is the main ZIP code for Boulder, MT?

The primary ZIP code for Boulder, MT is 59632. The city uses area code 406 for phone service.

What county is Boulder, MT in?

Boulder is located in Jefferson County, Montana.

How many ZIP codes are in Boulder, MT?

Boulder, MT has 1 ZIP code.

What is the ZIP code for Boulder, Montana's downtown area near the Jefferson County seat?

Boulder, Montana's downtown area uses ZIP code 59632, which serves the entire town in Jefferson County.

What ZIP code should I use for mailing packages to businesses in Boulder, MT near the historic mining district?

All addresses in Boulder, MT, including those in the historic mining areas, use the ZIP code 59632.