Lewis and Clark County's 2026 population is estimated at 75,763, reflecting a 0.42% growth rate over the past year (World Population Review estimate based on U.S. Census Bureau data). Lewis and Clark County is the 6th largest county in Montana. The 2010 population was 63,578 and has grown 19.17% since 2010.
Data after 2023 is projected based on recent change
Overall: 41.8 years
Female: 42.6 years
Male: 40.9 years
There are 57,898 adults, (14,843 of whom are seniors) in Lewis and Clark County.
Female: 37,002 (50.4%)
Male: 36,462 (49.6%)
The racial composition of Lewis and Clark County includes 90.65% White, and smaller percentages for Native American, other race, Black or African American, Asian and multiracial populations.
| Race | Population ↓ | Percentage (of total) |
|---|---|---|
| White | 66,597 | 90.65% |
| Two or more races | 4,478 | 6.1% |
| Native American | 965 | 1.31% |
| Other race | 648 | 0.88% |
| Black or African American | 417 | 0.57% |
| Asian | 359 | 0.49% |
Lewis and Clark County 's average per capita income is $53,368. Household income levels show a median of $78,237. The poverty rate stands at 8.06%.
| Name | Median ↓ | Mean |
|---|---|---|
| Married Families | $115,896 | $136,674 |
| Families | $104,950 | $126,549 |
| Households | $78,237 | $104,055 |
| Non Families | $47,346 | $67,560 |
Average Income
Median Household Income
Poverty Rate
