County · Montana

Lewis and Clark County, Montana

Lewis and Clark County, Montana. Lewis and Clark County had 75,331 residents in 2025 by the Census Bureau's estimate, up 6.1% since 2020, faster than Montana (+5.6%). It holds 18 places (2 cities, villages and boroughs and 16 census-designated) and 17 census tracts. GEOID 30049.

Lewis and Clark County is one of the 3 counties of the Helena, MT metropolitan statistical area (the Census Bureau's July 2023 delineation).

Residents, July 2025 estimate

75,331

Census Bureau estimate (no margin published)
2020 Census count: 70,973 · ACS 2020-2024: 73,464

Median household income

$78,237

±$3,203 (90% margin)
Montana: $72,509

Median home value

$393,500

±$9,364 (90% margin)
Montana: $375,800

Median gross rent

$1,102

±$46 (90% margin)
Montana: $1,081

How many people live in Lewis and Clark County, and is it growing?

The 2020 Census counted 70,973 residents in Lewis and Clark County. The Census Bureau estimates 75,331 for July 1, 2025, up 6.1% since 2020, faster than Montana (+5.6%). The 2020-2024 American Community Survey puts the population at 73,464 over 3,458 square miles of land.

July 2020→2021 +1,333 (72,514)
2021→2022 +1,150 (73,664)
2022→2023 +1,119 (74,783)
2023→2024 +309 (75,092)
2024→2025 +239 (75,331)

Lewis and Clark County in Montana. Boundaries: Census Bureau 2024.

Counts, ACS 2020-2024 5-year estimates, with the change from 2015-2019
Measure	Lewis and Clark County	Montana	Change since 2015-2019
Total population	73,464	1,116,875	+5,659
Households	31,215±362	458,859	+3,322
Average household size	2.30±0.03	2.37	−0.07
Housing units	34,082±56	528,419	+2,461

Lewis and Clark County's population since 2000

From 55,716 in 2000 to 75,331 in 2025: up 35.2%. The 2000, 2010 and 2020 figures are census counts. The 2005 figure is the Census Bureau's intercensal estimate, revised to fit the 2000 and 2010 counts and drawn on 2010 boundaries; 2015 and 2025 are July 1 estimates made from the census before them.

2000 Census 55,716
2005 (estimate) 58,529
2010 Census 63,395
2015 (estimate) 66,308
2020 Census 70,973
2025 (estimate) 75,331

Source: The 2000, 2010 and 2020 Census counts and the Census Bureau's population estimates (intercensal 2000-2010, Vintage 2020, Vintage 2025) · Census population estimates

Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); PEP Vintage 2025 (CO-EST2025); 2020 Census · Check it at data.census.gov

What cities and towns are in Lewis and Clark County?

Lewis and Clark County holds 18 places: 2 cities, villages and boroughs (incorporated places) and 16 census-designated places. The largest is Helena with 35,138 residents (2025 estimate). Places that cross a county line are listed with the share of their 2020 residents who live in this county.

Places in Lewis and Clark County, ACS 2020-2024 5-year estimates. Ring: estimate with a coefficient of variation over 40%.

Helena	city	32,091	33,639±59	$71,036	$387,300	8.8%	100%
Helena Valley Southeast	CDP	9,168	9,108±1,009	$74,075	$331,500	8.3%	100%
Helena Valley West Central	CDP	8,670	8,056±922	$90,082	$367,200	7.1%	100%
Helena Valley Northwest	CDP	4,705	5,183±716	$100,605	$404,200	2.6%	100%
Helena Valley Northeast	CDP	3,813	4,659±850	$140,517	$576,700	5.2%	100%
East Helena	city	1,944	1,702±422	$60,417	$290,700	16.5%	100%
Helena West Side	CDP	1,331	1,417±415	$66,921	$402,300	5.9%	100%
Lincoln	CDP	998	908±219	$62,813	$380,900	6.4%	100%
AugustaGEOID 3003025	CDP	316	165±69	$43,611	$208,300	7.9%	100%
UnionvilleGEOID 3075905	CDP	206	412±197	$84,750	$485,500	1.5%	100%
YorkGEOID 3082525	CDP	94	182±125	not published	$423,700	0.0%	100%
MarysvilleGEOID 3048250	CDP	82	160±150	$99,167	$287,500	3.8%	100%
RiminiGEOID 3062650	CDP	51	118±86	not published	$265,400	0.0%	100%
GilmanGEOID 3030750	CDP	48	12±13	not published	not published	0.0%	100%
Canyon CreekGEOID 3012025	CDP	47	27±41	not published	not published	100.0%	100%
CraigGEOID 3018025	CDP	39	172±162	not published	not published	17.4%	100%
Wolf CreekGEOID 3081400	CDP	25	12±13	$72,500	not published	0.0%	100%
Milford ColonyGEOID 3049600	CDP	2	40±74	not published	not published	100.0%	100%

Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); 2020 place-by-county parts · Check it at data.census.gov

Who lives in Lewis and Clark County?

The median resident of Lewis and Clark County is 41.8 years old; 21.2% are under 18 and 20.2% are 65 or older. The largest group is non-Hispanic white residents at 88.6%, then non-Hispanic residents of two or more races at 4.7%. 1.9% of residents were born outside the United States.

Age, origin and education, ACS 2020-2024 5-year estimates. Race groups are non-Hispanic; Hispanic includes any race.
Measure	Lewis and Clark County	Montana	Change since 2015-2019
Median age	41.8±0.5	40.4	+1.0
Under 18 years	21.2%	21.0%	–
65 years and over	20.2%±0.1 pts	20.1%	–
Hispanic or Latino (any race)	4.0%	4.6%	+0.7 pts
White alone, not Hispanic	88.6%±0.6 pts	83.6%	−2.8 pts
Black or African American alone, not Hispanic	0.5%±0.1 pts	0.4%	+0.2 pts
Asian alone, not Hispanic	0.5%±0.2 pts	0.8%	no clear change
American Indian and Alaska Native alone, not Hispanic	1.3%±0.3 pts	5.3%	–
Native Hawaiian and Other Pacific Islander alone, not Hispanic	0.0%±0.1 pts	0.0%	–
Two or more races, not Hispanic	4.7%±0.7 pts	4.7%	–
Some other race alone, not Hispanic	0.4%±0.3 pts	0.5%	–
Born outside the United States	1.9%±0.4 pts	2.3%	+0.7 pts
Speak a language other than English at home (age 5+)	2.8%±0.6 pts	4.2%	–
Civilian veterans (age 18+)	9.7%±0.9 pts	9.0%	–
With a disability	14.8%±1.3 pts	14.5%	–
No health insurance coverage	5.7%±1.0 pts	8.6%	no clear change
High school graduate or higher (age 25+)	94.8%±1.0 pts	94.6%	–
Bachelor's degree or higher (age 25+)	43.0%±1.7 pts	35.2%	+2.9 pts
Graduate or professional degree (age 25+)	14.6%±1.2 pts	12.0%	–
Moved from another state in the past year	3.9%±0.8 pts	3.7%	–

Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profiles DP02, DP05) · Check it at data.census.gov

What do households in Lewis and Clark County earn?

Half of Lewis and Clark County's 31,215 households earn less than $78,237 a year (±$3,203), against $72,509 in Montana. In 2015-2019 it was $80,969 in 2024 dollars; the margins of error cannot tell the two periods apart. 8.1% of residents live below the poverty line.

Income and poverty in 2024 dollars, ACS 2020-2024 5-year estimates
Measure	Lewis and Clark County	Montana	Change since 2015-2019
Median household income	$78,237±$3,203	$72,509	no clear change
Mean household income	$104,055±$3,868	$98,908	–
Per capita income	$44,837±$1,572	$41,711	+$2,373
People below the poverty line	8.1%±1.2 pts	11.5%	−2.3 pts
Children under 18 below the poverty line	5.7%±2.5 pts	12.7%	−8.6 pts
Households receiving SNAP	7.8%±1.2 pts	7.8%	–
Households with a broadband subscription	90.3%±1.5 pts	89.4%	–

Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov

What does housing cost in Lewis and Clark County?

Owners occupy 70.1% of Lewis and Clark County's occupied homes and renters 29.9%. The median owner-occupied home is valued at $393,500 by its owner (±$9,364). The median renter pays $1,102 a month including utilities, and 31.6% of renters pay 35% or more of their income on rent.

Housing, ACS 2020-2024 5-year estimates
Measure	Lewis and Clark County	Montana	Change since 2015-2019
Median home value (owner-occupied)	$393,500±$9,364	$375,800	+$94,441
Median gross rent	$1,102±$46	$1,081	+$77
Renters paying 35% or more of income on rent	31.6%±3.7 pts	35.5%	no clear change
Median monthly owner costs, with a mortgage	$1,883±$46	$1,798	–
Owner-occupied homes	70.1%±1.8 pts	69.2%	no clear change
Housing units	34,082±56	528,419	+2,461
Homeowner vacancy rate	0.4%±0.3 pts	0.9%	–
Rental vacancy rate	3.3%±1.9 pts	5.3%	–
Single-family detached homes	66.0%±1.9 pts	68.8%	–
Mobile homes	9.6%±1.0 pts	9.4%	–
Built 2020 or later	3.2%±0.7 pts	2.3%	–
Built 1939 or earlier	13.1%±1.2 pts	12.8%	–

Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP04) · Check it at data.census.gov

How many new homes is Lewis and Clark County building?

Builders took permits for 193 new housing units across Lewis and Clark County in 2025 (55 single-family), 2.6 per 1,000 residents.

2019 204 units
2020 250 units
2021 212 units
2022 144 units
2023 314 units
2024 444 units
2025 193 units

Source: Building Permits Survey, annual county files 2019-2025, U.S. Census Bureau · Census Building Permits Survey

How do people in Lewis and Clark County get to work?

68.1% of Lewis and Clark County's workers drive alone and 14.5% work from home. The average trip to work takes 18.3 minutes. The unemployment rate in 2020-2024 averaged 3.2%.

Work and commuting, ACS 2020-2024 5-year estimates
Measure	Lewis and Clark County	Montana	Change since 2015-2019
In the labor force (age 16+)	63.9%±1.2 pts	62.9%	–
Unemployment rate	3.2%±0.8 pts	3.6%	no clear change
Drove alone to work	68.1%±2.2 pts	71.1%	–
Carpooled	10.8%±1.7 pts	9.7%	–
Public transportation	0.2%±0.2 pts	0.6%	–
Walked	4.3%±1.0 pts	3.9%	–
Worked from home	14.5%±1.5 pts	12.5%	+8.8 pts
Mean travel time to work	18.3 min±1.0	19.1 min	+1.5 min

Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov

What are Lewis and Clark County's census tracts?

Lewis and Clark County is divided into 17 census tracts. Among those with a reliable estimate, median household income runs from $49,265 (Tract 1) to $113,250 (Tract 3).

Census tracts of Lewis and Clark County, ACS 2020-2024 5-year estimates; sort by any column

Tract 130049000100	Lincoln (14%)	2,165	1,615±220	$49,265	$358,300	$792	12.3%
Tract 230049000200	Helena Valley Northwest (31%)	5,916	6,472±827	$98,417	$399,400	$1,133	4.3%
Tract 330049000300	Helena Valley Northeast (12%)	3,026	2,899±290	$113,250	$449,300	$1,125	6.8%
Tract 430049000400	Helena (42%)	6,349	6,968±873	$86,111	$411,500	$1,261	10.3%
Tract 5.0130049000501	Helena Valley West Central	4,415	4,581±664	$79,893	$338,000	$1,227	5.9%
Tract 5.0330049000503	Helena (68%)	4,784	4,802±568	$73,029	$417,600	$1,588	8.3%
Tract 5.0430049000504	Helena	2,862	3,187±449	$72,147	$339,200	$998	11.8%
Tract 630049000600	Helena West Side (19%)	2,880	2,622±350	$93,105	$524,600	$1,356	9.5%
Tract 7.0130049000701	Helena (68%)	2,151	2,580±443	$74,443	$417,600	$1,113	2.1%
Tract 7.0230049000702	Helena (99%)	5,043	5,036±524	$69,267	$390,000	$987	15.2%
Tract 830049000800	Helena (92%)	4,089	4,027±415	$50,733	$394,400	$826	13.4%
Tract 930049000900	Helena	3,814	4,026±443	$68,311	$340,200	$1,066	8.6%
Tract 1030049001000	Helena (96%)	3,988	3,941±463	$86,123	$387,200	$1,130	3.6%
Tract 11.0130049001101	Helena (69%)	3,071	3,130±250	$72,868	$362,800	$1,193	4.9%
Tract 11.0230049001102	Helena (97%)	3,887	4,544±517	$84,886	$418,700	$1,086	7.3%
Tract 12.0130049001201	East Helena (57%)	7,030	7,255±857	$82,887	$377,500	$1,067	6.7%
Tract 12.0230049001202	Helena Valley Southeast (39%)	5,503	5,779±643	$84,554	$432,200	$737	7.8%

Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) · Check it at data.census.gov

How does Lewis and Clark County compare with Montana's other counties?

Lewis and Clark County's rank among Montana's counties with a reliable estimate (1 = highest)
Measure	Rank
Population	6th of 56
Growth 2020-2025	18th of 56
Residents per square mile	7th of 56
Median household income	5th of 56
Median home value	12th of 56
Median gross rent	8th of 56
Poverty rate	47th of 56
Bachelor's degree or higher	3rd of 56
Median age	40th of 56

Every county in Montana

Source: PlainCities ranks from the American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) and PEP Vintage 2025 · How ranks are computed

How these figures are made: methodology and release checks · reading a margin of error · every state · corrections

Not on this page: crime, weather and schools for Lewis and Clark County are other agencies' records. Crime: the FBI's Crime Data Explorer · climate: NOAA's U.S. Climate Normals · schools: the National Center for Education Statistics' school search.