Lewis and Clark County is home to 73,464 people in Montana. That puts it in the top 6% of US counties for household income. 2% of people here were born outside the United States. The population is up 32% since 2000. There are 21 people per square mile. About 43% of adults have finished a four-year degree.
At a glance
Average income
median household income $78,237, near the US median
US median: $82,259
Older
median age 41.8
US median: 38.9
More educated
43% hold a bachelor's degree
US average: 36%
Less affordable
home values up 104%, inflation adjusted
US median home: $376,019
Unique to this place
What stands out about Lewis and Clark County
What changed most since 1990
Median home value (2024 dollars)$148,564 → $393,500(+165%)US over the same years: +67%
White share95.9% → 88.6%(−7.3 pts)US over the same years: −17.8 pts
Shares are "alone or in combination": a person with both Medicare and Medicaid counts in each, so categories overlap and do not sum to 100%.
Section 09 · Service history
Veterans
Veterans by period of service, 2024
Gulf War (2001 or later)35.1%(1,960)
US avg: 26.4%
Gulf War (1990s)26.2%(1,463)
US avg: 24.3%
Vietnam era33.5%(1,870)
US avg: 33.1%
Korean War2.7%(151)
US avg: 4.5%
World War II0.5%(30)
US avg: 1%
Share of the 5,583 veterans here. A veteran who served across eras counts in each, so shares can total more than 100%. Peacetime-only service is included in the total but not shown as an era.
BAR + DOT: THIS PLACE · TICK: US AVERAGE
Over time
Lewis and Clark County, decade by decade
Lewis and Clark County population, inflation-adjusted income and home value, education, and diversity by year
Year
Population
Median household income
Median home value
Bachelor's degree+
Diversity score
1990
47,495
$63,383
$148,564
27.8%
10.0
2000
55,716
$68,057
$192,731
31.6%
13.5
2010
63,395
$72,271
$266,855
34.7%
17.9
2020
70,973
$80,070
$319,857
42.5%
28.9
2024
73,464
$78,237
$393,500
43.0%
26.1
Census years come from the decennial census and the latest year from the American Community Survey, so part of any change between those two rows can reflect the different surveys. Dollar figures are adjusted for inflation to 2024 dollars; a figure ending in "+" was at the Census Bureau's reporting cap that year. The diversity score runs from 0 to 100; see how it's calculated.
How many people live in Lewis and Clark County, Montana?
Lewis and Clark County, Montana has about 73,464 residents according to the 2024 American Community Survey.
What is the median household income in Lewis and Clark County, Montana?
The typical household in Lewis and Clark County, Montana earns about $78,237 a year. Half of households make more than that, and half make less.
Is Lewis and Clark County, Montana expensive?
In Lewis and Clark County, Montana, the median home is worth about $393,500, and the typical rent is about $1,102 a month.
How educated are people in Lewis and Clark County, Montana?
About 43.0% of adults age 25 and over in Lewis and Clark County, Montana hold a bachelor's degree or higher.
What is the poverty rate in Lewis and Clark County, Montana?
About 8.1% of people in Lewis and Clark County, Montana live below the federal poverty line.
Has Lewis and Clark County, Montana grown since 1990?
Yes, Lewis and Clark County, Montana has grown since 1990. The population has added about 25,969 residents, a change of about 55 percent over that period.
