Lewis and Clark County Demographics

A map of Lewis and Clark County's Population by Race

Race	2024 Pop	2020 Pop	2024 %	2020 %
White	65,103	62,063	88.6%	87.4%
Multiracial	3,420	3,930	4.7%	5.5%
Hispanic	2,958	2,599	4.0%	3.7%
Native American/Other	1,239	1,564	1.7%	2.2%
Black	385	266	0.5%	0.4%
Asian	359	551	0.5%	0.8%

Lewis and Clark County, Montana has an estimated population of 73,464, an increase from the 70,973 recorded in the 2020 Census. The population is 88.6% White, 4.7% Multiracial, 4.0% Hispanic, 1.7% Native American/Other, 0.5% Black, and 0.5% Asian. This demographic dot map shows the population of Lewis and Clark County, with one dot drawn for each person counted by the Census, color-coded by race.

Lewis and Clark has become less racially diverse since the 2020 Census. It is considerably less diverse than Montana overall. Demographers use a diversity index to measure the probability that two randomly selected individuals belong to different racial or ethnic groups. In Lewis and Clark County, that probability was 23.0% in 2020 and 21.1% in the most recent ACS estimates.

Lewis and Clark County is ranked the 6th most populous county in Montana, out of 56 counties. Lewis and Clark County was ranked the 6th most populous county in the 2020 Census.

Lewis and Clark County's White Population

65,103 residents of Lewis and Clark County, or 88.6% of the population, identify as White. The share of White residents in Lewis and Clark County is slightly higher than in Montana overall, where 83.6% of the population is White. Lewis and Clark County ranks 37th statewide in terms of White residents as a share of the population, out of 56 counties.

Since the 2020 Census, Lewis and Clark County's White population has grown by an estimated 4.9%. White residents' share of Lewis and Clark County's population has increased from 87.4% to 88.6%.

Lewis and Clark County is more White than neighboring Powell County (86.8% White), Cascade County (82.4% White), and Pondera County (78.9% White). Lewis and Clark County is less White than neighboring Teton County (91.5% White), and Jefferson County (90.6% White).

Lewis and Clark County's Black Population

385 residents of Lewis and Clark County, or 0.5% of the population, identify as Black. The share of Black residents in Lewis and Clark County is comparable to the share in Montana overall, where 0.4% of the population is Black. Lewis and Clark County ranks 14th statewide in terms of Black residents as a share of the population, out of 56 counties.

Since the 2020 Census, Lewis and Clark County's Black population has grown by an estimated 44.7%. Black residents' share of Lewis and Clark County's population has remained roughly unchanged at 0.5%.

Lewis and Clark County is more Black than neighboring Powell County (0.4% Black), Teton County (0.3% Black), Jefferson County (0% Black), and Pondera County (0% Black). Lewis and Clark County is less Black than neighboring Cascade County (1.3% Black).

Lewis and Clark County's Asian Population

359 residents of Lewis and Clark County, or 0.5% of the population, identify as Asian. The share of Asian residents in Lewis and Clark County is comparable to the share in Montana overall, where 0.8% of the population is Asian. Lewis and Clark County ranks 7th statewide in terms of Asian residents as a share of the population, out of 56 counties.

Since the 2020 Census, Lewis and Clark County's Asian population has declined by an estimated 34.8%. Asian residents' share of Lewis and Clark County's population has remained roughly unchanged at 0.5%.

Lewis and Clark County is more Asian than neighboring Teton County (0% Asian), and Jefferson County (0.4% Asian). Lewis and Clark County is less Asian than neighboring Powell County (1.5% Asian), Cascade County (1% Asian), and Pondera County (1% Asian).

Lewis and Clark County's Hispanic Population

2,958 residents of Lewis and Clark County, or 4.0% of the population, identify as Hispanic. The share of Hispanic residents in Lewis and Clark County is comparable to the share in Montana overall, where 4.6% of the population is Hispanic. Lewis and Clark County ranks 12th statewide in terms of Hispanic residents as a share of the population, out of 56 counties.

Since the 2020 Census, Lewis and Clark County's Hispanic population has grown by an estimated 13.8%. Hispanic residents' share of Lewis and Clark County's population has remained roughly unchanged at 4.0%.

Lewis and Clark County is more Hispanic than neighboring Powell County (2.7% Hispanic), Teton County (2% Hispanic), Jefferson County (3% Hispanic), and Pondera County (2.6% Hispanic). Lewis and Clark County is less Hispanic than neighboring Cascade County (5.3% Hispanic).

Lewis and Clark County's Native American/Other Population

1,239 residents of Lewis and Clark County, or 1.7% of the population, identify as American Indian/Alaska Native/Native Hawaiian/Pacific Islander/Other. The share of Native American/Other residents in Lewis and Clark County is slightly lower than in Montana overall, where 5.9% of the population is Native American/Other. Lewis and Clark County ranks 21st statewide in terms of Native American/Other residents as a share of the population, out of 56 counties.

Since the 2020 Census, Lewis and Clark County's Native American/Other population has declined by an estimated 20.8%. Native American/Other residents' share of Lewis and Clark County's population has decreased from 2.2% to 1.7%.

Lewis and Clark County is less Native American/Other than neighboring Powell County (5.1% Native American/Other), Teton County (2.1% Native American/Other), Cascade County (4.1% Native American/Other), and Pondera County (14.6% Native American/Other).

Lewis and Clark County's Multiracial Population

3,420 residents of Lewis and Clark County, or 4.7% of the population, identify as Multiracial. The share of Multiracial residents in Lewis and Clark County is comparable to the share in Montana overall, where 4.7% of the population is Multiracial. Lewis and Clark County ranks 10th statewide in terms of Multiracial residents as a share of the population, out of 56 counties.

Since the 2020 Census, Lewis and Clark County's Multiracial population has declined by an estimated 13.0%. Multiracial residents' share of Lewis and Clark County's population has decreased from 5.5% to 4.7%.

Lewis and Clark County is more Multiracial than neighboring Powell County (3.5% Multiracial), Teton County (4.1% Multiracial), Jefferson County (4.4% Multiracial), and Pondera County (3% Multiracial). Lewis and Clark County is less Multiracial than neighboring Cascade County (6% Multiracial).

Sources: Most recent population estimates are from the 2020-2024 American Community Survey 5-Year Estimates. 2020 population counts and map data are from 2020 Census State Redistricting Data. Geographic data are from Census TIGER/Line Shapefiles.