Boulder Flag

Boulder

County Seat:
Yes
Area (mi²):
1.124
State:
Montana

Boulder is a city located in Jefferson County, Montana. Boulder has a 2026 population of 1,355. It is also the county seat of Jefferson County. Boulder is currently growing at a rate of 1.88% annually and its population has increased by 12.45% since the most recent census, which recorded a population of 1,205 in 2020.

The median household income in Boulder is $72,500 with a poverty rate of 3.76%. The median age in Boulder is 41.4 years: 43.2 years for males, and 41 years for females. For every 100 females there are 125.3 males.

1.4K
Total Population
1,205
Density (mi²)
25 1.88%
Growth

Boulder Population

Boulder Population

Data after 2023 is projected based on recent change

Year ↓
Population
Growth
Annual Change
20261,355251.88%
20251,330251.92%
20241,305171.32%
20231,288171.34%
20221,271373%
20211,234292.41%
20201,20550.42%
20191,276131.03%
20181,263151.2%
20171,248141.13%
20161,234231.9%
20151,21190.75%
20141,20280.67%
20131,194151.27%
20121,17910.08%
20111,178-5-0.42%
20101,18010.08%

Median Age

Overall: 41.4 years
Female: 41 years
Male: 43.2 years

Boulder Adults

There are 1,023 adults, (254 of whom are seniors) in Boulder.

Sex Ratio

Female: 570 (44.4%)
Male: 714 (55.6%)

Demographics

The racial composition of Boulder includes 91.2% White, 3.58% Native American, and smaller percentages for Two or more races, other race and multiracial populations.

Population by Race

Race
Population ↓
Percentage (of total)
White1,17191.2%
Native American463.58%
Two or more races352.73%
Other race322.49%
Race
Population ↓
Percentage (of total)
Other race191.48%
White171.32%
Race
Population ↓
Percentage (of total)
White1,15489.88%
Native American463.58%
Two or more races352.73%
Other race131.01%

Boulder Marital Status

Economics and Income Statistics

Boulder 's average per capita income is $38,850. Household income levels show a median of $72,500. The poverty rate stands at 3.76%.

Families: A family includes the owner or renter of the home along with everyone related to them - whether through birth, marriage, or adoption. This includes relatives like spouses, children, parents, siblings, grandparents, and any other family members.
Households: A household includes all the people who occupy a housing unit (such as a house or apartment) as their usual place of residence.
Non Families: A nonfamily household is either someone living alone or when the owner/renter lives with people they aren't related to, like roommates.
Name
Median ↓
Mean
Married Families$104,414-
Families$103,086$103,154
Households$72,500$86,175
Non Families$57,601$50,665

$38,850

Average Income

$72,500

Median Household Income

3.76%

Poverty Rate

Nearby Cities

Sources

  1. US Census State Population Estimates - Most recent state estimates from the Census Bureau's Population Estimates Program
  2. US Census County Population Estimates - Most recent county estimates from the Census Bureau's Population Estimates Program
  3. American Community Survey (2009 - 2013)
  4. Census QuickFacts
  5. Historical Populations of States and Counties (1790 - 1990)