Counties in Colorado by population aged 18 to 64
Crowley County had the highest population aged 18 to 64 of 64 counties in 2020, at 73.4%. Custer County had the lowest, at 51.2%. The median was 58.9% and the figure for Colorado was 63%. Source: the U.S. Census Bureau.
Map of counties, 2020
- Under 53
- 53 to 56
- 56 to 59
- 59 to 62
- 62 to 65
- 65 and over
Top 40 counties, 2020
Full ranking
| Rank | Counties | 2020 (%) | Change on 2019 |
|---|---|---|---|
| 1 | Crowley County | 73.4 | -1.9 pts |
| 2 | Summit County | 70.4 | -0.3 pts |
| 3 | Denver County | 69 | -0.2 pts |
| 4 | Gunnison County | 68.3 | -0.1 pts |
| 5 | San Miguel County | 66.3 | -0.4 pts |
| 6 | Lake County | 66.1 | -0.9 pts |
| 7 | Gilpin County | 66 | -0.4 pts |
| 8 | Eagle County | 66 | -0.4 pts |
| 9 | Boulder County | 65.7 | -0.2 pts |
| 10 | Bent County | 65.4 | -0.9 pts |
| 11 | Grand County | 65.1 | -0.2 pts |
| 12 | Pitkin County | 64.7 | -0.2 pts |
| 13 | Routt County | 64.2 | -0.7 pts |
| 14 | Clear Creek County | 64 | -0.1 pts |
| 15 | Broomfield County | 63.6 | +0.2 pts |
| 16 | Larimer County | 63.4 | -0.4 pts |
| 17 | Adams County | 63.2 | +0.1 pts |
| 18 | Jefferson County | 63 | -0.2 pts |
| 19 | Arapahoe County | 62.7 | -0.2 pts |
| 20 | El Paso County | 62.7 | -0.2 pts |
| 21 | Lincoln County | 62.5 | +0.4 pts |
| 22 | Park County | 62.5 | -1.3 pts |
| 23 | Logan County | 62.1 | -1.6 pts |
| 24 | La Plata County | 61.4 | -0.8 pts |
| 25 | Douglas County | 61.4 | +0.1 pts |
| 26 | Garfield County | 61 | -0.5 pts |
| 27 | Weld County | 60.9 | -0.2 pts |
| 28 | San Juan County | 60.8 | -1.7 pts |
| 29 | Fremont County | 60.6 | -0.8 pts |
| 30 | Elbert County | 60.4 | -0.4 pts |
| 31 | Alamosa County | 60 | -0.7 pts |
| 32 | Moffat County | 58.9 | -0.6 pts |
| 33 | Dolores County | 58.9 | 0 pts |
| 34 | Teller County | 58.5 | -1.2 pts |
| 35 | Mesa County | 58.3 | -0.5 pts |
| 36 | Pueblo County | 57.9 | -0.6 pts |
| 37 | Chaffee County | 57.7 | -0.8 pts |
| 38 | Jackson County | 57.4 | -2.4 pts |
| 39 | Ouray County | 56.9 | -0.9 pts |
| 40 | Las Animas County | 56.8 | -0.8 pts |
| 41 | Rio Blanco County | 56.7 | -0.6 pts |
| 42 | Morgan County | 56.7 | -0.4 pts |
| 43 | Mineral County | 56.4 | +1.5 pts |
| 44 | Saguache County | 56.3 | +1.2 pts |
| 45 | Prowers County | 56.2 | -1.1 pts |
| 46 | Washington County | 55.7 | -0.2 pts |
| 47 | Kit Carson County | 55.6 | -0.3 pts |
| 48 | Otero County | 55.2 | +0.1 pts |
| 49 | Montezuma County | 55.1 | -0.8 pts |
| 50 | Rio Grande County | 54.9 | -0.5 pts |
| 51 | Yuma County | 54.8 | -0.1 pts |
| 52 | Montrose County | 54.1 | -0.5 pts |
| 53 | Phillips County | 53.5 | -0.7 pts |
| 54 | Archuleta County | 53.4 | -0.7 pts |
| 55 | Costilla County | 53.4 | -1 pts |
| 56 | Cheyenne County | 53 | -0.9 pts |
| 57 | Baca County | 53 | 0 pts |
| 58 | Kiowa County | 52.8 | -0.6 pts |
| 59 | Delta County | 52.2 | -1.2 pts |
| 60 | Conejos County | 51.9 | -0.7 pts |
| 61 | Sedgwick County | 51.8 | -1.1 pts |
| 62 | Huerfano County | 51.7 | -0.6 pts |
| 63 | Hinsdale County | 51.7 | +0.6 pts |
| 64 | Custer County | 51.2 | 0 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
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 Colorado by population aged 18 to 64, 2020) [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 Colorado by population aged 18 to 64, 2020. 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/colorado-counties?period=2020. 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 Colorado by population aged 18 to 64, 2020. 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/colorado-counties?period=2020.
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 Colorado by population aged 18 to 64, 2020 [Dataset]. Available at: https://www.census.gov/programs-surveys/popest/data/data-sets.html, via Invokely: https://invokely.ai/rankings/population-18-64/colorado-counties?period=2020 (Accessed: 12 October 2026).
BibTeX
@misc{census_counties_in_colorado_by_2020,
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 Colorado by population aged 18 to 64, 2020}},
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/colorado-counties?period=2020. 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 Colorado by population aged 18 to 64, 2020
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/colorado-counties?period=2020
Y2 - 2026/10/12
N1 - Accessed via Invokely, https://invokely.ai/rankings/population-18-64/colorado-counties?period=2020.
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 -
Use this data in your AI agent
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Rank Counties in Colorado by population aged 18 to 64 using official data, and cite the source.
rank_places {"indicator":"population_18_64_share","level":"province","within":"Colorado","limit":10}
GET https://invokely.ai/api/v1/rank?indicator=population_18_64_share&level=province&within=Colorado&limit=10Questions
Which county has the highest population aged 18 to 64?
Crowley County, with 73.4% in 2020, according to the U.S. Census Bureau.
Which county has the lowest population aged 18 to 64?
Custer County, with 51.2% in 2020.
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.