Data / Rankings / Population aged 18 to 64 / Counties in Montana

Counties in Montana by population aged 18 to 64

Gallatin County had the highest population aged 18 to 64 of 56 counties in 2014, at 68.2%. Prairie County had the lowest, at 53.5%. The median was 57.9% and the figure for Montana was 61.1%. Source: the U.S. Census Bureau.

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Highest68.2Gallatin County
Lowest53.5Prairie County
Median57.956 counties
Montana61.1History

Map of counties, 2014

Beaverhead County: 60.4 %Big Horn County: 55.6 %Blaine County: 56.3 %Broadwater County: 57.6 %Carbon County: 59.1 %Carter County: 57 %Cascade County: 60.8 %Chouteau County: 56.1 %Custer County: 58.9 %Daniels County: 54.2 %Dawson County: 60.8 %Deer Lodge County: 61.7 %Fallon County: 58.6 %Fergus County: 56.6 %Flathead County: 59.8 %Gallatin County: 68.2 %Garfield County: 54.6 %Glacier County: 58 %Golden Valley County: 57 %Granite County: 55.7 %Hill County: 59.6 %Jefferson County: 60 %Judith Basin County: 59.6 %Lake County: 55.4 %Lewis and Clark County: 62 %Liberty County: 57.9 %Lincoln County: 56.4 %McCone County: 57.6 %Madison County: 58.3 %Meagher County: 56.3 %Mineral County: 56.6 %Missoula County: 66.3 %Musselshell County: 58.4 %Park County: 61.6 %Petroleum County: 54.4 %Phillips County: 56.8 %Pondera County: 55.5 %Powder River County: 58.7 %Powell County: 65.4 %Prairie County: 53.5 %Ravalli County: 56.1 %Richland County: 62.2 %Roosevelt County: 58 %Rosebud County: 57.9 %Sanders County: 55.1 %Sheridan County: 58.7 %Silver Bow County: 62.1 %Stillwater County: 58.6 %Sweet Grass County: 54.6 %Teton County: 55.2 %Toole County: 65.5 %Treasure County: 55.4 %Valley County: 56.6 %Wheatland County: 54.1 %Wibaux County: 55.3 %Yellowstone County: 61.1 %
  • Under 55
  • 55 to 56
  • 56 to 58
  • 58 to 59
  • 59 to 61
  • 61 and over
%, 2014. Source: Invokely calculation with data from U.S. Census Bureau. Boundaries: U.S. Census Bureau cartographic boundary files.

All counties, 2014

Gallatin County: 68.2 %Gallatin County68.2Missoula County: 66.3 %Missoula County66.3Toole County: 65.5 %Toole County65.5Powell County: 65.4 %Powell County65.4Richland County: 62.2 %Richland County62.2Silver Bow County: 62.1 %Silver Bow County62.1Lewis and Clark County: 62 %Lewis and Clark County62Deer Lodge County: 61.7 %Deer Lodge County61.7Park County: 61.6 %Park County61.6Yellowstone County: 61.1 %Yellowstone County61.1Cascade County: 60.8 %Cascade County60.8Dawson County: 60.8 %Dawson County60.8Beaverhead County: 60.4 %Beaverhead County60.4Jefferson County: 60 %Jefferson County60Flathead County: 59.8 %Flathead County59.8Judith Basin County: 59.6 %Judith Basin County59.6Hill County: 59.6 %Hill County59.6Carbon County: 59.1 %Carbon County59.1Custer County: 58.9 %Custer County58.9Powder River County: 58.7 %Powder River County58.7Sheridan County: 58.7 %Sheridan County58.7Stillwater County: 58.6 %Stillwater County58.6Fallon County: 58.6 %Fallon County58.6Musselshell County: 58.4 %Musselshell County58.4Madison County: 58.3 %Madison County58.3Roosevelt County: 58 %Roosevelt County58Glacier County: 58 %Glacier County58Liberty County: 57.9 %Liberty County57.9Rosebud County: 57.9 %Rosebud County57.9McCone County: 57.6 %McCone County57.6Broadwater County: 57.6 %Broadwater County57.6Carter County: 57 %Carter County57Golden Valley County: 57 %Golden Valley County57Phillips County: 56.8 %Phillips County56.8Valley County: 56.6 %Valley County56.6Fergus County: 56.6 %Fergus County56.6Mineral County: 56.6 %Mineral County56.6Lincoln County: 56.4 %Lincoln County56.4Meagher County: 56.3 %Meagher County56.3Blaine County: 56.3 %Blaine County56.3Ravalli County: 56.1 %Ravalli County56.1Chouteau County: 56.1 %Chouteau County56.1Granite County: 55.7 %Granite County55.7Big Horn County: 55.6 %Big Horn County55.6Pondera County: 55.5 %Pondera County55.5Treasure County: 55.4 %Treasure County55.4Lake County: 55.4 %Lake County55.4Wibaux County: 55.3 %Wibaux County55.3Teton County: 55.2 %Teton County55.2Sanders County: 55.1 %Sanders County55.1Garfield County: 54.6 %Garfield County54.6Sweet Grass County: 54.6 %Sweet Grass County54.6Petroleum County: 54.4 %Petroleum County54.4Daniels County: 54.2 %Daniels County54.2Wheatland County: 54.1 %Wheatland County54.1Prairie County: 53.5 %Prairie County53.5Gallatin County: 68.2 %Gallatin County68.2Missoula County: 66.3 %Missoula County66.3Toole County: 65.5 %Toole County65.5Powell County: 65.4 %Powell County65.4Richland County: 62.2 %Richland County62.2Silver Bow County: 62.1 %Silver Bow County62.1Lewis and Clark County: 62 %Lewis and Clark County62Deer Lodge County: 61.7 %Deer Lodge County61.7Park County: 61.6 %Park County61.6Yellowstone County: 61.1 %Yellowstone County61.1Cascade County: 60.8 %Cascade County60.8Dawson County: 60.8 %Dawson County60.8Beaverhead County: 60.4 %Beaverhead County60.4Jefferson County: 60 %Jefferson County60Flathead County: 59.8 %Flathead County59.8Judith Basin County: 59.6 %Judith Basin County59.6Hill County: 59.6 %Hill County59.6Carbon County: 59.1 %Carbon County59.1Custer County: 58.9 %Custer County58.9Powder River County: 58.7 %Powder River County58.7Sheridan County: 58.7 %Sheridan County58.7Stillwater County: 58.6 %Stillwater County58.6Fallon County: 58.6 %Fallon County58.6Musselshell County: 58.4 %Musselshell County58.4Madison County: 58.3 %Madison County58.3Roosevelt County: 58 %Roosevelt County58Glacier County: 58 %Glacier County58Liberty County: 57.9 %Liberty County57.9Rosebud County: 57.9 %Rosebud County57.9McCone County: 57.6 %McCone County57.6Broadwater County: 57.6 %Broadwater County57.6Carter County: 57 %Carter County57Golden Valley County: 57 %Golden Valley County57Phillips County: 56.8 %Phillips County56.8Valley County: 56.6 %Valley County56.6Fergus County: 56.6 %Fergus County56.6Mineral County: 56.6 %Mineral County56.6Lincoln County: 56.4 %Lincoln County56.4Meagher County: 56.3 %Meagher County56.3Blaine County: 56.3 %Blaine County56.3Ravalli County: 56.1 %Ravalli County56.1Chouteau County: 56.1 %Chouteau County56.1Granite County: 55.7 %Granite County55.7Big Horn County: 55.6 %Big Horn County55.6Pondera County: 55.5 %Pondera County55.5Treasure County: 55.4 %Treasure County55.4Lake County: 55.4 %Lake County55.4Wibaux County: 55.3 %Wibaux County55.3Teton County: 55.2 %Teton County55.2Sanders County: 55.1 %Sanders County55.1Garfield County: 54.6 %Garfield County54.6Sweet Grass County: 54.6 %Sweet Grass County54.6Petroleum County: 54.4 %Petroleum County54.4Daniels County: 54.2 %Daniels County54.2Wheatland County: 54.1 %Wheatland County54.1Prairie County: 53.5 %Prairie County53.5
%. Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-12.

Full ranking

RankCounties2014 (%)Change on 2013
1Gallatin County68.2-0.3 pts
2Missoula County66.3-0.6 pts
3Toole County65.50 pts
4Powell County65.4-0.1 pts
5Richland County62.2-0.5 pts
6Silver Bow County62.1-0.1 pts
7Lewis and Clark County62-0.5 pts
8Deer Lodge County61.7-0.3 pts
9Park County61.6-0.7 pts
10Yellowstone County61.1-0.3 pts
11Cascade County60.8-0.3 pts
12Dawson County60.8-0.5 pts
13Beaverhead County60.4-0.9 pts
14Jefferson County60-0.8 pts
15Flathead County59.8-0.7 pts
16Judith Basin County59.6-0.3 pts
17Hill County59.6-0.5 pts
18Carbon County59.1-0.1 pts
19Custer County58.9-0.5 pts
20Powder River County58.7-0.1 pts
21Sheridan County58.7-0.2 pts
22Stillwater County58.6-1 pts
23Fallon County58.6-1 pts
24Musselshell County58.4-0.4 pts
25Madison County58.3-0.9 pts
26Roosevelt County58-0.4 pts
27Glacier County58-0.1 pts
28Liberty County57.9+0.2 pts
29Rosebud County57.9-0.5 pts
30McCone County57.6-0.1 pts
31Broadwater County57.6-1.1 pts
32Carter County57-0.8 pts
33Golden Valley County57-2 pts
34Phillips County56.8-0.4 pts
35Valley County56.6-0.1 pts
36Fergus County56.6-0.2 pts
37Mineral County56.6-0.6 pts
38Lincoln County56.4-1.2 pts
39Meagher County56.3-1.4 pts
40Blaine County56.3-0.1 pts
41Ravalli County56.1-0.8 pts
42Chouteau County56.1-0.5 pts
43Granite County55.7-0.8 pts
44Big Horn County55.6-0.4 pts
45Pondera County55.5-0.4 pts
46Treasure County55.4-1.3 pts
47Lake County55.4-0.6 pts
48Wibaux County55.3-1.3 pts
49Teton County55.2-0.5 pts
50Sanders County55.1-0.9 pts
51Garfield County54.6-0.3 pts
52Sweet Grass County54.6-0.3 pts
53Petroleum County54.4-0.9 pts
54Daniels County54.2-0.7 pts
55Wheatland County54.1-1 pts
56Prairie County53.5-1.3 pts

Other periods

About this ranking

Residents aged 18 to 64 as a percentage of total population on 1 July. United States: Census Bureau county population estimates by age; states and the nation are sums of their counties.

Not comparable with working-age shares for ages 15 to 64 used in EU and World Bank statistics.

Every value in the ranking comes from the same publisher and the same period, so the counties are compared on one definition. Equal values share a rank.

How to cite

U.S. Census Bureau. Population Estimates Program, county population by age and sex: residents aged 18 to 64 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Retrieved 2026-10-12.

Citation styles

The publisher is the author. Invokely is named only as the place the figures were read, where a style asks for it.

APA 7

U.S. Census Bureau. (2026). Population Estimates Program, county population by age and sex: residents aged 18 to 64 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties (Counties in Montana by population aged 18 to 64, 2014) [Data set]. Retrieved October 12, 2026, from https://www.census.gov/programs-surveys/popest/data/data-sets.html

MLA 9

Population Estimates Program, county population by age and sex: residents aged 18 to 64 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties, Counties in Montana by population aged 18 to 64, 2014. U.S. Census Bureau, 25 June 2026, https://www.census.gov/programs-surveys/popest/data/data-sets.html. Invokely, https://invokely.ai/rankings/population-18-64/montana-counties?period=2014. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Census Bureau. 2026. Population Estimates Program, county population by age and sex: residents aged 18 to 64 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. Counties in Montana by population aged 18 to 64, 2014. Dataset. Accessed October 12, 2026. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Also distributed by Invokely, https://invokely.ai/rankings/population-18-64/montana-counties?period=2014.

Harvard

U.S. Census Bureau (2026) Population Estimates Program, county population by age and sex: residents aged 18 to 64 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties, Counties in Montana by population aged 18 to 64, 2014 [Dataset]. Available at: https://www.census.gov/programs-surveys/popest/data/data-sets.html, via Invokely: https://invokely.ai/rankings/population-18-64/montana-counties?period=2014 (Accessed: 12 October 2026).

BibTeX
@misc{census_counties_in_montana_by_2014,
  author = {{U.S. Census Bureau}},
  title = {{Population Estimates Program, county population by age and sex: residents aged 18 to 64 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties: Counties in Montana by population aged 18 to 64, 2014}},
  year = {2026},
  howpublished = {Data set},
  url = {https://www.census.gov/programs-surveys/popest/data/data-sets.html},
  urldate = {2026-10-12},
  note = {Accessed via Invokely, https://invokely.ai/rankings/population-18-64/montana-counties?period=2014. Publisher attribution: U.S. Census Bureau. Population Estimates Program, county population by age and sex: residents aged 18 to 64 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Retrieved 2026-10-12.},
}
RIS
TY  - DATA
AU  - U.S. Census Bureau
TI  - Population Estimates Program, county population by age and sex: residents aged 18 to 64 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties: Counties in Montana by population aged 18 to 64, 2014
PY  - 2026
DA  - 2026/06/25
PB  - U.S. Census Bureau
DB  - Invokely
UR  - https://www.census.gov/programs-surveys/popest/data/data-sets.html
L2  - https://invokely.ai/rankings/population-18-64/montana-counties?period=2014
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/population-18-64/montana-counties?period=2014.
N1  - Publisher attribution: U.S. Census Bureau. Population Estimates Program, county population by age and sex: residents aged 18 to 64 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Retrieved 2026-10-12.
ER  -
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Questions

Which county has the highest population aged 18 to 64?

Gallatin County, with 68.2% in 2014, according to the U.S. Census Bureau.

Which county has the lowest population aged 18 to 64?

Prairie County, with 53.5% in 2014.

Where does this ranking come from?

Every value comes from one source and one period, so the places are comparable: U.S. Census Bureau, Population Estimates Program, county population by age and sex: residents aged 18 to 64 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. Retrieved 2026-10-12.

Population aged 18 to 64: other rankings

Counties in Montana: more rankings