Lewis and Clark County, Montana Demographics 2026

Population Overview

Lewis and Clark County is located in Montana with a total population of 72,580. It is the 6th most populous county out of 56 in Montana.

Age Demographics

The median age in Lewis and Clark County is 41.3 years. This is 3% higher than the state median of 40.2 years.

Economy, Income & Housing

The median household income in Lewis and Clark County is $74,543. This is 7% higher than the state median of $69,922. Compared to the national median of $78,538, household income here is 5% lower. The poverty rate stands at 8.7%. This is 28% lower than the state poverty rate of 12.0%. The unemployment rate is 3.5%. This is 7% lower than the state rate of 3.8%. The median home value is $358,200. Housing costs are 6% higher than the state median of $338,100. The home-value-to-income ratio is 4.8x. 69.7% of occupied housing units are owner-occupied.

Race & Ethnicity

Lewis and Clark County has a predominantly White (non-Hispanic) population, comprising 89.2% of all residents. Hispanic or Latino residents account for 3.9%.

Education

42.8% 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 cities in the state for educational attainment. This is 24% higher than the state rate of 34.5%. Nationally, 35.0% of adults hold at least a bachelor's degree. The high school graduation rate (or equivalent) is 94.8%.