Jefferson County, Montana Demographics
Population trends, housing costs, income, commuting, and health, all on one page.
Jefferson County, MT Population Density Map and Area Scores
Area Score
Health, income and education, each graded from F to A+. Explore interactive maps for deeper analysis.
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B
Health Around averageHealthier than 88% of counties in Montana
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B
Income Around averageWealthier than 82% of counties in Montana
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B
Education Around averageAmong the top 5 best educated counties in Montana
Source: Map AI Methodology
Population: density and quick facts
| Metric | Jefferson County | Montana Avg | U.S. Average |
|---|---|---|---|
| Population | 12,778 | 1,116,812 | 337,468,954 |
| Population density (per sq mi) | 7.7 | 7.6 | 86.4 |
| Population growth (%/yr) | 1.18% | 1.09% | 0.59% |
| Median age | 47.8 | 40.7 | 37.3 |
| Households | 5,002 | 458,835 | 130,235,071 |
Population in Jefferson County grew by 14.5% from 2009 to 2024, reaching 12,778 in 2024.
Population Growth 2009–2024
Race & Ethnicity
Age & Sex
The largest generation in Jefferson County is Gen X, aged 45–60, at 25.0% of residents. That is 5.5 points above Montana as a whole.
- Gen Z 13–28 2,136 16.7% -4.8 pts
- Millennials 29–44 2,228 17.4% -3.0 pts
- Gen X 45–60 3,189 25.0% +5.5 pts
- Boomers 61–79 2,979 23.3% +3.9 pts
Residents by birth cohort, from the 2025 age distribution. The right-hand figure is how far each cohort's share sits above or below Montana, in percentage points. Children younger than Gen Z and the generations before the Boomers are counted in the population but not shown here, so these shares do not add up to 100%.
Male and female share
Women are 49.0% of the people living in Jefferson County and men 51.0%.
- Women 49.0% Montana 49.4%
- Men 51.0% Montana 50.6%
How many residents match a customer profile?
Residents matching this profile
100% of everyone living in Jefferson County
Pick an age range and a women/men split and the figure above answers with how many residents that profile reaches.
Economy
Jefferson County has a the economy index of B, which means it is quite prosperous.
| Metric | Jefferson County | Montana Avg | U.S. Average |
|---|---|---|---|
| Median household income | $93,727 | $72,476 | $80,455 |
| Income growth (%/yr) | 5.05% | 5.17% | 4.80% |
| Unemployment rate | 4.2% | 3.6% | 5.2% |
The median household income in Jefferson County is about 29% higher than in Montana.
Housing
| Metric | Jefferson County | Montana Avg | U.S. Average |
|---|---|---|---|
| Median home price | $354,971 | $249,140 | $248,835 |
| Median rent | $925 | $1,081 | $1,407 |
| Homeownership rate | 84.2% | 69.2% | 65.2% |
The median home price in Jefferson County is about 32.0 years' worth of rent — buying at the median price costs roughly as much as paying the median rent of $925 per month for that long.
Commute Time & Mobility
Commuters in Jefferson County spend about 37 minutes on the road round trip each working day. Over a typical 250-day work year, that adds up to roughly 156 hours, about 6.5 full days, spent commuting.
| Metric | Jefferson County | Montana Avg | U.S. Average |
|---|---|---|---|
| One-way commute (min) | 18.7 | 16.0 | 22.4 |
| Round-trip commute (min) | 37.4 | 32.1 | 44.8 |
| Yearly time spent (hours) | 156 | 134 | 187 |
| Estimated yearly cost | $4,828 | $4,143 | $5,790 |
| Work from home | 12.7% | 12.5% | 15.0% |
| Highway traffic (vehicles/day) | 2,492 | 2,162 | 8,813 |
| Local road traffic (vehicles/day) | 972 | 403 | 1,355 |
Fastest commutes among counties in
Montana:
Treasure County (7.2 min), Rosebud County (8.2 min), Fallon County (8.4 min).
Slowest:
Broadwater County (30.3 min), Stillwater County (27.8 min), Granite County (23.3 min).
The average commute time in Jefferson County is 19 minutes, longer than the 16 minutes in Montana.
Estimated yearly cost applies a single national wage rule of thumb (U.S. Bureau of Labor Statistics average hourly earnings), not a measurement of wages in this area. Traffic volume figures come from proprietary Ticon and TrafficZoom data.
Education & Households
Jefferson County has a education index of B, which means it is quite educated.
| Metric | Jefferson County | Montana Avg | U.S. Average |
|---|---|---|---|
| Bachelor's degree or higher | 31.1% | 31.3% | 31.6% |
| Average household size | 2.50 | 2.37 | 2.53 |
Highest education index among counties in
Montana:
Gallatin County (0.4), Missoula County (0.3), Lewis and Clark County (0.3).
Lowest:
Liberty County (0.2), Toole County (0.2), Wheatland County (0.2).
Health
Jefferson County has a health index of B, which means it is quite healthy.
| Metric | Jefferson County | Montana Avg | U.S. Average |
|---|---|---|---|
| Life expectancy (years) | 79.8 | 79.0 | 78.3 |
| Self-rated poor health | 11.9% | 14.7% | 16.3% |
| Smokers | 16.6% | 18.8% | 19.0% |
Highest health index among counties in
Montana:
Gallatin County (0.8), Missoula County (0.8), Granite County (0.8).
Lowest:
Glacier County (0.7), Big Horn County (0.8), Roosevelt County (0.8).
Jefferson County, MT Compared With Nearby Counties
How Jefferson County, MT compares with the 2 counties closest to it.
| Area | Population | Median household income | Median home price | Commute |
|---|---|---|---|---|
| Jefferson County, MT | 12,778 | $93,727 #1/3 | $354,971 #1/3 | 18.7 min #3/3 |
| Silver Bow County, MT | 35,793 | $61,292 | $165,062 | 13.0 min |
| Lewis and Clark County, MT | 73,430 | $79,279 | $310,934 | 16.2 min |
Frequently Asked Questions
Common questions about Jefferson County, Montana.
What is the population of Jefferson County, Montana?
About 12,778 people live in Jefferson County, Montana, in 5,002 households of 2.5 people on average. The median age is 47.8, so residents are older than the U.S. median of 37.3 by about 11 years.
How densely populated is Jefferson County, Montana?
Averaged over its land area, Jefferson County, Montana has 8 people per square mile, a density typical of rural areas. That is about 9% of the U.S. average of 86.
How affordable is housing in Jefferson County, Montana?
The median home costs 3.8 times the median household income ($354,971 against $93,727), compared with 3.1 times nationally. A ratio of about 3 is traditionally considered affordable. Median rent of $925 a month takes about 12% of the median household's income, below the 30% level at which HUD considers renters cost-burdened.
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