Lewis and Clark County, Montana
Located in Montana, Lewis and Clark County has a population of 73,464 residents and a median age of 41.8 years, making it the #763 most populous county out of 3,222 nationwide. In terms of economic indicators, the county has a poverty rate of 8.1%. The median home value is $393,500, and the median household income is $78,237, which is 4% above the national median.
Demographics
Lewis and Clark County has a population of 73,464, making it the #763 most populous county in the US. The median age is 41.8 years, which is 7.5% above the national median.
Population Trend
Rankings →Year-over-Year Population Growth
Age & Sex Distribution
Race & Ethnicity
Nativity
Geographic Mobility (Past Year)
Economy
The median household income in Lewis and Clark County is $78,237, ranking #659 out of 3,222 counties — 4.1% above the national median. The poverty rate is 8.1% and unemployment stands at 3.2%.
Median Household Income Trend
Rankings →Income Distribution
Industry of Employment
Occupation
Housing
The median home value in Lewis and Clark County is $393,500 (+39.6% vs national). Renters pay a median of $1,102/mo and the homeownership rate is 70.1%.
Median Home Value Trend
Rankings →Household Type
Education
In Lewis and Clark County, 43.0% of adults age 25+ hold a bachelor's degree or higher, which is 27.7% above the national average, ranking #199 out of 3,222 counties.
Bachelor's Degree or Higher Trend
Rankings →Health & Wellbeing
Life expectancy in Lewis and Clark County is 78.3 years. 12.0% of adults report poor or fair health and 9.5% lack health insurance. Data from County Health Rankings (2025).
Life Expectancy Trend
Substance Use
11.3% of adults in Lewis and Clark County smoke , 30.1% are obese , and 25.6% report excessive drinking. The drug overdose death rate is 13.9 per 100,000.
Adult Smoking Trend
Safety
The homicide rate in Lewis and Clark County is 3.7 per 100,000 and the suicide rate is 24.2 per 100,000. Motor vehicle deaths occur at a rate of 11.8 per 100,000.
Homicide Rate Trend
Families & Children
9.6% of children in Lewis and Clark County live in poverty and the infant mortality rate is 3.9 per 1,000 live births. The teen birth rate is 11.3 per 1,000 females age 15–19.
Infant Mortality Trend
Civic & Transportation
Voter turnout in Lewis and Clark County is 78.9%. The mean commute time is 20.1 min, which is 27.2% below the national average.
Voter Turnout Trend
Mean Commute Time Trend
Rankings →Elections
In the 2024 presidential election, Lewis and Clark County voted Republican with a margin of 5.7%. The vote was 45.4% Dem / 51.1% Rep. Compared to 2020, the margin shifted 1.8 toward Republicans .
Vote Share Over Time
About Lewis and Clark County, Montana
Lewis and Clark County, Montana has a total population of 73,464, making it the 763rd most populous county in the United States. The median age in Lewis and Clark County is 41.8 years, which is 7.5% above the national median of 38.9 years.
The median household income in Lewis and Clark County is $78,237, which ranks #659 of 3,222 counties nationwide. This is 4.1% above the national median of $75,149. The poverty rate is 8.1%, lower than the national rate of 12.6%. The unemployment rate stands at 3.2%.
The median home value in Lewis and Clark County is $393,500, 39.6% above the national median. Renters in Lewis and Clark County pay a median gross rent of $1,102 per month. The homeownership rate is 70.1%, compared to the national rate of 64.4%.
In Lewis and Clark County, 43.0% of residents aged 25 and older hold a bachelor's degree or higher, 27.7% above the national average of 33.7%. Health insurance coverage stands at 94.3% of the population. The average commute time for workers is 20.1 min.
Lewis and Clark County is a diverse community. The largest racial or ethnic group is White (non-Hispanic) at 88.6% of the population, followed by Two or More Races (4.7%) and Hispanic or Latino (4.0%).
All data for Lewis and Clark County, Montana comes from the U.S. Census Bureau's American Community Survey (ACS) 5-Year Estimates. These figures are estimates based on survey sampling and are subject to margin of error. For the most detailed and up-to-date data, visit the Census Bureau's official data portal.