Sweet Grass County, Montana Population 2026
Updated April 2026 · US Census ACS 2023 5-Year Estimates · 39th-largest in Montana
The population of Sweet Grass County, Montana is 3,713 as of the 2023 American Community Survey, making it the 39th-largest county in Montana. The median household income is $69,426, the median home value is $295,500, and the median age is 44.0.
The population of Sweet Grass County has grown 3.9% since 2010 (3,617 → 3,757), a +0.27% annualized rate.
3,713
Population
+0.27%
Annual growth
2
People / sq mi
$69,426
Median Income
$295,500
Median Home Value
Sweet Grass County covers 1,856 sq mi of land at 2.0 people per square mile.
About Sweet Grass County, MT
Sweet Grass County is a county in Montana with a population of 3,713. It ranks #39 among counties in Montana by population. The median age is 44.0, older than the national median. The population is 50.2% male and 49.8% female.
The median household income in Sweet Grass County is $69,426, below the US median of $74,580. 3.7% of residents live below the federal poverty level. Home values sit at a median of $295,500, with monthly rent averaging $1,073. The homeownership rate of 76.2% is higher than the national rate of 64.8%.
Educational attainment in Sweet Grass County reflects 23.1% of adults 25 and older holding a bachelor's degree or higher, below the national average of 34.3%. Roughly 13.1% of workers primarily work from home, similar to the national work-from-home rate of 14.2%. The average commute is 23.7 minutes each way.
Sweet Grass County Population History (2010-2024)
The county of Sweet Grass County had a population of 3,617 in 2010 and 3,757 in 2024, a 3.9% growth over 14 years. The peak was 3,757 in 2024. Average annual growth rate: 0.28%.
3,757
Population (2024)
3,617
Population (2010)
3,757
Peak (2024)
0.28%
Avg Annual Growth
| Year | Population |
|---|---|
| 2010 | 3,617 |
| 2011 | 3,584 |
| 2012 | 3,579 |
| 2013 | 3,657 |
| 2014 | 3,637 |
| 2015 | 3,618 |
| 2016 | 3,610 |
| 2017 | 3,668 |
| 2018 | 3,701 |
| 2019 | 3,717 |
| 2020 | 3,670 |
| 2021 | 3,702 |
| 2022 | 3,724 |
| 2023 | 3,749 |
| 2024 | 3,757 |
Race & Ethnicity
| White | 90.6% |
| Black or African American | 1.3% |
| Asian | 0.0% |
| Hispanic or Latino (any race) | 4.4% |
| Two or More Races | 0.0% |
Age & Sex
44.0
Median Age
49.8%
Female
50.2%
Male
23.4%
Age 65+
Age Distribution
Children (under 15): 15.8% · Seniors (65+): 23.4%
Income & Poverty
| Median household income | $69,426$-496 vs state |
| Mean household income | $94,999 |
| Per-capita income | $39,756 |
| Poverty rate | 3.7%-3.4% vs state |
| Unemployment rate | 1.3% |
| Employment-to-population | 60.0% |
Top Industries by Employment
The largest employment sector in Sweet Grass County is agriculture, accounting for 20.6% of workers.
How residents commute
2.2%
Drive alone
3.4%
Carpool
70.3%
Public transit
13.1%
Work from home
23.7 min
Avg commute
Housing
$295,500$-42,600 vs state
Median home value
$1,073
Median rent
76.2%
Homeownership rate
1,929
Total housing units
77.6%
Occupied
22.4%
Vacant
23.8%
Renter-occupied
Social & access
90.8%
With health insurance
91.4%
With broadband internet
45.4%
Foreign-born
9.7%
Veterans (18+)
16.7%
With a disability
96.9%
Speak language other than English at home
Education
96.4%
High School+
23.1%
Bachelor's+
Largest cities in Montana
Other counties in Montana
Part of Montana
Metro areas in Montana
County rankings
Frequently Asked Questions
Sweet Grass County, Montana has a population of 3,713 according to the US Census Bureau's 2023 American Community Survey 5-year estimates, making it the 39th-largest county in Montana. Population density is 2 people per square mile.
The population of Sweet Grass County has grown 3.9% since 2010 (3,617 → 3,757), a +0.27% annualized rate.
The median household income in Sweet Grass County, Montana is $69,426, with mean (average) household income of $94,999 and per-capita income of $39,756. 3.7% of residents live below the federal poverty level.
In Sweet Grass County, the largest racial and ethnic groups are White (90.6%), Hispanic or Latino (4.4%), Black or African American (1.3%). Figures are from the US Census Bureau's 2023 ACS 5-year estimates and reflect self-reported responses.
The median age in Sweet Grass County, Montana is 44.0 years. Residents are 49.8% female and 50.2% male.
The median home value in Sweet Grass County is $295,500 and median monthly rent is $1,073. 76.2% of occupied housing units are owner-occupied. The county has 1,929 total housing units, 22.4% of which are vacant.
The largest employment sector in Sweet Grass County, Montana is agriculture, forestry, fishing, and mining, employing 20.6% of workers. The unemployment rate is 1.3%.
Billings is among the largest cities associated with Sweet Grass County, Montana, with a population of 118,321.
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Statewide data for Montana
Population, race, income, age, and trends across Montana
Data from the American Community Survey (ACS) 5-Year estimates.
Source: U.S. Census Bureau ACS, 2026.