Lewis and Clark County, Montana Demographics 2026

Name: Lewis and Clark County, Montana Demographics
Creator: U.S. Census Bureau
License: https://www.census.gov/data/developers/about/terms-of-service.html

Lewis and Clark County, Montana has a population of 73,464, the 6th most populous county in Montana. The median household income is $78,237 and the median home value is $393,500. The poverty rate is 8.1%.

Data vintage: U.S. Census Bureau ACS 2020–2024 5-Year Estimates · refreshed July 2026 · Methodology & source notes

Lewis and Clark County Quick Facts

Population 73,464

Median Household Income $78,237

Median Home Value $393,500

Poverty Rate 8.1%

Unemployment Rate 3.2%

Median Age 41.8 years

Homeownership Rate 70.1%

Affordability Ratio 5.0x

Bachelor's Degree+ 43.0%

High School Graduation 94.8%

Cities/Places 18

Population 73,464 6th of 56

Median Income $78,237 8% higher than state

Poverty Rate 8.1%

Unemployment 3.2%

How Lewis and Clark County Changed

Change from the 2019–2023 ACS period to 2020–2024. These are rolling five-year estimates, not year-over-year measurements.

Metric	2019–2023	2020–2024	Change
Population	72,580	73,464	+1.2%
Median household income	$74,543	$78,237	+5.0%
Median home value	$358,200	$393,500	+9.9%

Median Household Income

Lewis and Clark

$78,237

$72,509

National

$80,734

Median Home Value

Lewis and Clark

$393,500

$375,800

National

$332,700

Economy & Housing

Household Income Distribution

Under $25K 10.3%

$25K-$50K 19.5%

$50K-$100K 31.5%

$100K+ 38.8%

Detailed income brackets

Under $10K

2.8%

$10K-$15K

2.1%

$15K-$20K

1.9%

$20K-$25K

3.5%

$25K-$30K

3.7%

$30K-$35K

3.6%

$35K-$40K

4.4%

$40K-$45K

4.2%

$45K-$50K

3.5%

$50K-$60K

7.3%

$60K-$75K

10.6%

$75K-$100K

13.6%

$100K-$125K

10.1%

$125K-$150K

8.9%

$150K-$200K

10.4%

$200K+

9.4%

Employment

3.2% Unemployment Rate State: 3.6%|National: 5.2%

63.9% Labor Force Participation

Housing Overview

Owner 70.1%

Renter 29.9%

Affordability Index Expensive

5.0x home value to income ratio

Median gross rent $1,102/mo 16.9% of median household income annually

People & Demographics

Age Distribution

Under 18

21.2%

18-34

19.5%

35-54

25.1%

55-74

26.7%

75+

7.4%

Race & Ethnicity

Diversity Index

Very Low Diversity

A less diverse community where one racial or ethnic group represents a large majority.

State average: 29 | National average: 61

Education

Educational Attainment (Adults 25+)

Cities & Places in Lewis and Clark County

City	Population	Median Income	Poverty	Home Value
Helena	33,639	$71,036	8.8%	$387,300
Helena Valley Southeast	9,108	$74,075	8.3%	$331,500
Helena Valley West Central	8,056	$90,082	7.1%	$367,200
Helena Valley Northwest	5,183	$100,605	2.6%	$404,200
Helena Valley Northeast	4,659	$140,517	5.2%	$576,700
East Helena	1,702	$60,417	16.5%	$290,700
Helena West Side	1,417	$66,921	5.9%	$402,300
Lincoln	908	$62,813	6.4%	$380,900
Unionville	412	$84,750	1.5%	$485,500
York	182	N/A	0.0%	$423,700
Craig	172	N/A	17.4%	N/A
Augusta	165	$43,611	7.9%	$208,300
Marysville	160	$99,167	3.8%	$287,500
Rimini	118	N/A	0.0%	$265,400
Milford Colony	40	N/A	100.0%	N/A
Canyon Creek	27	N/A	100.0%	N/A
Gilman	12	N/A	0.0%	N/A
Wolf Creek	12	$72,500	0.0%	N/A

Explore Montana Rankings

Cities by Population All cities ranked by size Richest Cities Ranked by median income Most Educated By bachelor's degree rate Most Affordable By housing affordability

Population Overview

Lewis and Clark County is located in Montana with a total population of 73,464. It is the 6th most populous county out of 56 in Montana. The county encompasses 18 Census-designated places.

Age Demographics

The median age in Lewis and Clark County is 41.8 years. This is 3% higher than the state median of 40.4 years.

Economy, Income & Housing

The median household income in Lewis and Clark County is $78,237. This is 8% higher than the state median of $72,509. It is also 3% lower than the national median of $80,734. The poverty rate stands at 8.1%. This is 30% lower than the state poverty rate of 11.5%. The unemployment rate is 3.2%. This is 10% lower than the state rate of 3.6%. The median home value is $393,500. Housing costs are 5% higher than the state median of $375,800. The home-value-to-income ratio is 5.0x. 70.1% of occupied housing units are owner-occupied. This homeownership rate is 1% higher than the state average of 69.2%.

Race & Ethnicity

Lewis and Clark County has a predominantly White (non-Hispanic) population, comprising 88.6% of all residents. Hispanic or Latino residents account for 4.0%.

Education

43.0% of residents aged 25 and older hold a bachelor's degree or higher. This places Lewis and Clark County in the top 10% of all counties in the state for educational attainment. This is 22% higher than the state rate of 35.2%. Nationally, 35.7% of adults hold at least a bachelor's degree. The high school graduation rate (or equivalent) is 94.8%.

Data Sources & Methodology

All figures for Lewis and Clark County come from the U.S. Census Bureau's American Community Survey (ACS) 2020–2024 5-Year Estimates, with comparisons drawn against Montana and national averages from the same dataset. See our methodology page for how each metric is defined, or data.census.gov for official tables with margins of error.

Frequently Asked Questions

What is the population of Lewis and Clark County, Montana?

Lewis and Clark County has a population of 73,464, making it the 6th most populous county in Montana.

What is the median income in Lewis and Clark County?

The median household income in Lewis and Clark County is $78,237 with a poverty rate of 8.1%.

How many cities are in Lewis and Clark County, Montana?

Lewis and Clark County contains 18 Census-designated places.