Demographics of Stillwater County, Montana

Stillwater County, Montana had 9,445 people on July 1, 2025, by the Census Bureau’s estimate: +447 since July 2020. Age, income, poverty, housing and origin below come from the American Community Survey, averaged over 2020–2024, each with its margin of error.

Stillwater County, in four figures

9,445
Population: July 1, 2025, Vintage 2025 estimate.; +5.0%
Change since July 2020: +447 people.; 46.7 ±0.5
Median age: ACS 2020–⁠2024.; $84,732 ±$8,032
Median household income: ACS 2020–⁠2024, in 2024 dollars.

Population, year by year

July 1 estimates from the Census Bureau’s Vintage 2025. Each year's change is births less deaths, net moves from abroad and net moves from elsewhere in the country, with the Bureau's small residual. The 2020 row's components run 3 months, from the April census to July 1.

Stillwater County, Montana's population grew 5.0% from July 2020 to July 2025, against +3.1% nationally

The July 1 estimate of Stillwater County, Montana's resident population and the nation's, each year of the Census Bureau's Vintage 2025, as a share of its July 2020 level (= 100).

U.S. Census Bureau — Census Bureau population estimates — counties and Puerto Rico municipios, with components of change

About this chart

The figures

Stillwater County, Montana's population grew 5.0% from July 2020 to July 2025, against +3.1% nationally. The July 1 estimate of Stillwater County, Montana's resident population and the nation's, each year of the Census Bureau's Vintage 2025, as a share of its July 2020 level (= 100).
July 1	Population	Index	United States
2020	8,998	100.0	100.0
2021	9,022	100.3	100.2
2022	9,186	102.1	100.7
2023	9,238	102.7	101.6
2024	9,429	104.8	102.5
2025	9,445	105.0	103.1

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Population of Stillwater County, Montana on July 1 of each year, Vintage 2025
July 1	Population	Change	Births less deaths	From abroad	From elsewhere in the country
2020	8,998	+38	−12	0	+54
2021	9,022	+24	−44	0	+63
2022	9,186	+164	−23	−2	+185
2023	9,238	+52	+9	−1	+45
2024	9,429	+191	−6	0	+200
2025	9,445	+16	−4	−1	+22

Age, 2020–2024

The median age is 46.7 ±0.5: for men 46.6 ±0.5 and for women 46.8 ±1.1. Shares are of everyone the survey counts, in the Bureau’s sex-by-age table (B01001).

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People in Stillwater County by age, ACS 2020–2024
Age	People	Share	Montana	United States
Under 5	386 ±10	4.2% ±0.1	5.2% ±<0.1	5.6% ±<0.1
5 to 17	1,539 ±124	16.8% ±1.3	15.8% ±0.2	16.3% ±<0.1
18 to 24	582 ±100	6.3% ±1.1	9.0% ±0.2	9.1% ±<0.1
25 to 44	1,859 ±118	20.2% ±1.3	25.8% ±0.2	26.9% ±<0.1
45 to 64	2,502 ±146	27.2% ±1.6	24.1% ±0.2	24.8% ±<0.1
65 and over	2,314 ±189	25.2% ±2.1	20.1% ±0.2	17.2% ±<0.1

Income and poverty, 2020–2024

Median household income is $84,732 ±$8,032, and income per person $50,603 ±$3,961, in 2024 dollars. The median is $72,509 ±$761 in Montana and $80,734 ±$166 in the United States.

Households by income

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Households in Stillwater County by income, ACS 2020–2024
Household income	Households	Share	Montana	United States
Under $25,000	501 ±96	13.1% ±2.5	15.0% ±0.4	14.6% ±<0.1
$25,000 to $49,999	703 ±127	18.5% ±3.3	19.4% ±0.5	16.7% ±<0.1
$50,000 to $74,999	437 ±88	11.5% ±2.3	17.3% ±0.4	15.5% ±<0.1
$75,000 to $99,999	497 ±99	13.0% ±2.6	13.6% ±0.4	12.6% ±<0.1
$100,000 to $149,999	733 ±123	19.2% ±3.2	17.4% ±0.4	17.5% ±<0.1
$150,000 to $199,999	457 ±104	12.0% ±2.7	8.2% ±0.3	9.6% ±<0.1
$200,000 or more	482 ±113	12.7% ±2.9	9.0% ±0.3	13.4% ±0.1

Poverty by age

The poverty rate is the share of people whose family income is below the federal threshold for their family’s size, of everyone for whom the Bureau determines it (B17020).

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Poverty rate in Stillwater County by age, ACS 2020–2024
Age	Below poverty	Rate	Montana	United States
All ages	751 ±158	8.3% ±1.7	11.5% ±0.3	12.5% ±0.1
Under 18	126 ±54	6.7% ±2.8	12.7% ±0.6	16.1% ±0.1
18 to 59	336 ±95	7.9% ±2.2	11.7% ±0.4	11.6% ±0.1
60 and over	289 ±75	9.7% ±2.4	10.3% ±0.4	11.0% ±<0.1

Housing, 2020–2024

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Housing in Stillwater County, ACS 2020–2024
Measure	Stillwater County	Montana	United States
Housing units	4,657 ±23	528,419 ±3,257	143,775,355 ±10,234
Occupied	81.8% ±2.9	86.8% ±0.5	89.9% ±0.1
Vacant	18.2% ±2.8	13.2% ±0.3	10.1% ±0.1
Owner occupied	82.9% ±2.1	69.2% ±0.6	65.2% ±0.3
Renter occupied	17.1% ±2.8	30.8% ±0.4	34.8% ±0.1
Median home value	$405,800 ±$23,525	$375,800 ±$3,433	$332,700 ±$236
Median gross rent	$961 ±$47	$1,081 ±$14	$1,413 ±$2
Median year built	1986 ±3	1981 ±1	1980 ±1

Occupied and vacant are shares of all housing units; owner and renter occupied are shares of occupied units. Value and rent are medians in 2024 dollars.

Origin and place of birth, 2020–2024

Hispanic or Latino origin is not a race in the Census Bureau’s tables. Here the people of Hispanic origin, of any race, are one row, and everyone else is counted by race alone (B03002), so the rows add to the whole.

Hispanic origin and race

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People in Stillwater County by Hispanic origin and race, ACS 2020–2024
Origin	People	Share	Montana	United States
Hispanic or Latino	319 ±0	3.5% ±<0.1	4.6% ±<0.1	19.3% ±<0.1
White alone, not Hispanic	8,446 ±33	92.0% ±0.4	83.6% ±0.2	57.4% ±<0.1
Black alone, not Hispanic	0 to 8	0% to 0.1%	0.4% ±<0.1	11.9% ±<0.1
Asian alone, not Hispanic	13 to 55	0.1% to 0.6%	0.8% ±0.1	5.9% ±<0.1
American Indian and Alaska Native alone, not Hispanic	6 to 44	0.1% to 0.5%	5.3% ±0.1	0.5% ±<0.1
Native Hawaiian and Other Pacific Islander alone, not Hispanic	0 to 16	0% to 0.2%	< 0.1% ±<0.1	0.2% ±<0.1
Some other race alone, not Hispanic	2 to 26	< 0.1% to 0.3%	0.5% ±0.1	0.6% ±<0.1
Two or more races, not Hispanic	340 ±43	3.7% ±0.5	4.7% ±0.2	4.3% ±<0.1

A range (the estimate less and plus its margin) where the Bureau's estimate is too uncertain to state as one number: a coefficient of variation over 30%.

Place of birth and citizenship

“Born a citizen outside the states” counts people born in Puerto Rico, the island areas, or abroad to American parents. Naturalized citizens and those who are not citizens together make up the people born abroad (B05002).

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People in Stillwater County by place of birth and citizenship, ACS 2020–2024
Born	People	Share	Montana	United States
Born in the state	4,663 ±261	50.8% ±2.8	52.1% ±0.5	57.3% ±<0.1
Born in another state	4,361 ±255	47.5% ±2.8	44.8% ±0.4	26.9% ±<0.1
Born a citizen outside the states	7 to 75	0.1% to 0.8%	0.8% ±0.1	1.7% ±<0.1
Born abroad	117 ±30	1.3% ±0.3	2.3% ±0.1	14.1% ±<0.1
Naturalized citizens	97 ±28	1.1% ±0.3	1.2% ±0.1	7.4% ±<0.1
Not citizens	7 to 33	0.1% to 0.4%	1.1% ±0.1	6.8% ±<0.1

A range (the estimate less and plus its margin) where the Bureau's estimate is too uncertain to state as one number: a coefficient of variation over 30%.

Stillwater County among the counties of Montana

25th of 56 by population, July 2025. Every one is listed on the Montana page.

Counties of Montana near Stillwater County in population, July 2025
County	July 2025	Change since 2020
Richland County	11,377	−1.3%
Roosevelt County	10,242	−5.2%
Beaverhead County	10,043	+7.1%
Madison County	10,026	+15.8%
Deer Lodge County	9,709	+3.0%
Stillwater County	9,445	+5.0%
Dawson County	8,692	−2.6%
Broadwater County	8,493	+23.8%
Rosebud County	8,253	−0.7%
Valley County	7,385	−2.4%
Powell County	7,157	+3.1%

Elsewhere on the site

Sources

Census Bureau population estimates — counties and Puerto Rico municipios, with components of change — U.S. Census Bureau · U.S. Government work · retrieved September 25, 2026
American Community Survey 5-year estimates — table-based Summary File · U.S. Government work

Data retrieved September 25, 2026