• county
  • FIPS 30049
  • Largest town: Helena

Lewis and Clark County, Montana

Lewis and Clark County had 75,129 residents in the Census Vintage 2024 estimate, on 3,458.4 square miles of land. It ranks 6th of 56 in Montana by population and 14th by land area.

Population
75,129
#6 of 56 in Montana · #752 in US
Area
3,458.4 sq mi
#14 of 56 in Montana · #145 in US
Density
22 / sq mi
#8 of 56 in Montana · #2,185 in US
Median household income
$76,816
#4 of 56 in Montana · #585 in US

Census Vintage 2024 estimates · SAIPE 2023 income · 2024 Gazetteer land area

Lewis and Clark County within Montana. Pin: Helena.

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Lewis and Clark County population, land area and income

Lewis and Clark County had 75,129 residents in the Census Vintage 2024 estimate, on 3,458.4 square miles of land. It ranks 6th of 56 in Montana by population and 14th by land area. That works out to 21.7 people per square mile, below the US average of 96.3, and below the national county median.

The median county-equivalent in Montana has 7,814 residents, so Lewis and Clark County is 9.6 times that size.

Its SAIPE 2023 median household income of $76,816 is in the top quarter among 3,143 counties with an estimate.

National rank among 3,144

Population

75,129

3144th1st

752nd of 3,144 (US)

Land area

3,458 sq mi

3144th1st

145th of 3,144 (US)

Density

21.7 / sq mi

3144th1st

2185th of 3,144 (US)

Median household income

$76,816

3143rd1st

585th of 3,143 (US)

Rank within Montana (56)

Population

75,129

56th1st

6th of 56 (MT)

Land area

3,458 sq mi

56th1st

14th of 56 (MT)

Density

21.7 / sq mi

56th1st

8th of 56 (MT)

Median household income

$76,816

56th1st

4th of 56 (MT)

How Lewis and Clark County's population changed since 2020

Lewis and Clark County gained 3,950 residents between the July 2020 and July 2024 estimates, a rise of 5.5%. That ranks 16th of 56 in Montana for growth. The median Montana county changed by +2.8%, and the state as a whole by +4.6%.

Since the April 2020 estimates base, Lewis and Clark County recorded 2,899 births and 3,096 deaths, a natural change of -197. Net international migration added +124 and net domestic migration, people moving to or from other US counties, came to +4,203. The largest single component was domestic migration, which added 4,203 people.

71.2k202072.5k202173.7k202274.8k202375.1k2024
Census Vintage 2024 county estimates for July 1 of each year. The axis starts above zero so year-to-year changes are visible.

Components of change, April 2020 to July 2024

Births
2,899
Deaths
3,096
Net international migration
+124
Net domestic migration
+4,203
Change, July 2023 to July 2024
+317

Where Lewis and Clark County is

The Census internal point of Lewis and Clark County is at 47.122100, -112.382900. It sits in UTM zone 12N. The map shades Montana's 56 county-equivalents by population change from 2020 to 2024, darker for faster growth, with Lewis and Clark County outlined. Dots are towns of 1,000+ people with residents in it.

Liberty County: -1.2%Golden Valley County: +5.1%Dawson County: -2.1%Flathead County: +9.2%Beaverhead County: +6.7%Prairie County: +2.0%Garfield County: +0.9%Lewis and Clark County: +5.5%Sweet Grass County: +2.4%Wheatland County: -0.7%Ravalli County: +8.5%Jefferson County: +9.6%Carter County: -0.6%Chouteau County: -0.6%Custer County: +0.9%Teton County: +3.1%Granite County: +9.0%Deer Lodge County: +4.1%Cascade County: +0.1%Powder River County: +2.4%Meagher County: +7.3%Daniels County: -1.7%Glacier County: -1.8%Wibaux County: -2.7%Fallon County: -2.7%McCone County: -0.7%Sheridan County: -2.5%Missoula County: +3.5%Toole County: +3.7%Sanders County: +11.5%Roosevelt County: -5.6%Rosebud County: -1.3%Treasure County: -2.5%Yellowstone County: +3.9%Blaine County: -1.4%Musselshell County: +14.8%Broadwater County: +21.0%Powell County: +2.6%Fergus County: +3.4%Phillips County: +0.1%Gallatin County: +6.2%Silver Bow County: +2.6%Madison County: +12.6%Richland County: -4.4%Lake County: +6.9%Valley County: -1.7%Judith Basin County: +4.3%Hill County: -1.2%Big Horn County: -2.2%Stillwater County: +5.0%Carbon County: +9.4%Mineral County: +13.7%Petroleum County: +4.6%Pondera County: +3.4%Park County: +4.9%Lincoln County: +12.4%
Change 2020 to 2024
  1. < -1.4%
  2. < +0.9%
  3. < +3.9%
  4. < +7.3%
  5. ≥ +7.3%
no data

Orange pin: Lewis and Clark County internal point. Dark pin: Helena.

Internal point

Decimal
47.122100, -112.382900
DMS
47°07'19.56"N 112°22'58.44"W
UTM
12N 395104.7E 5219660.5N
Geohash
c82h4dm60
Plus code
85V94JC8+RR

Towns in Lewis and Clark County

2 incorporated places of 1,000+ people have residents in Lewis and Clark County, 36,968 people together, or 49% of the county. Each figure counts only the part of the town inside Lewis and Clark County; towns marked "part" extend into another county. The largest is Helena with 34,729.

  1. 01Helena34,729
  2. 02East Helena2,239
Census Vintage 2024 subcounty estimates, county parts of incorporated places (SUMLEV 157).

Counties bordering Lewis and Clark County

The Census 2024 county adjacency file lists 7 neighbors for Lewis and Clark County. The most populous is Flathead County, MT, with 114,527 residents. Distances run between Census internal points in a straight line.

Distance to Helena and the nearest big city

Helena is 40.9 miles SSE of Lewis and Clark County's internal point in a straight line. The nearest place of 100,000 or more is Billings, MT (population 121,483), 204.2 miles away. The nearest place of 10,000 or more is Helena, MT (population 34,729), 40.1 miles away.

Lewis and Clark County FIPS code

The FIPS code of Lewis and Clark County is 30049: state code 30 for Montana plus county code 049. Use it as text, with the leading zero, when joining Census, BLS, or CDC county tables. SAIPE lists its 2023 median household income as $76,816.

Questions people ask

What is the population of Lewis and Clark County, Montana?

The Census Vintage 2024 estimate for July 1, 2024 is 75,129. That is up 3,950 people (5.5%) from the July 2020 estimate of 71,179.

What is the FIPS code of Lewis and Clark County?

30049. The first two digits (30) are Montana; the last three (049) identify the county.

What is the largest town in Lewis and Clark County?

Helena, with 34,729 residents inside Lewis and Clark County in 2024.

Which counties border Lewis and Clark County?

7 county-equivalents border it in the Census 2024 adjacency file: Flathead County, MT; Cascade County, MT; Jefferson County, MT; Broadwater County, MT; Powell County, MT; Teton County, MT; Meagher County, MT.

Sources and data as of

Data as of: Census Vintage 2024 population estimates, 2024 Gazetteer land area and internal points, SAIPE 2023 median household income.

  1. 01Census Vintage 2024 county population estimates
  2. 02Census 2024 Gazetteer, counties
  3. 03Census SAIPE 2023 state and county estimates
  4. 04Census Vintage 2024 subcounty population estimates
  5. 05Census 2024 county adjacency file
  6. 06Census 2024 cartographic boundary file, counties (1:5,000,000)

How every number is computed: methodology. Spotted a wrong figure? Report an error.