Counties in Colorado by population under 18

Douglas County had the highest population under 18 of 64 counties in 2016, at 28%. Crowley County had the lowest, at 13%. The median was 20.5% and the figure for Colorado was 23%. Source: the U.S. Census Bureau.

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Median20.564 counties
Colorado23History

Map of counties, 2016

Adams County: 27.4 %Alamosa County: 23.8 %Arapahoe County: 24.4 %Archuleta County: 18.7 %Baca County: 20.5 %Bent County: 15.4 %Boulder County: 20 %Broomfield County: 23.8 %Chaffee County: 15.5 %Cheyenne County: 25.6 %Clear Creek County: 16.3 %Conejos County: 27.5 %Costilla County: 19.6 %Crowley County: 13 %Custer County: 15 %Delta County: 20.6 %Denver County: 20.3 %Dolores County: 19.6 %Douglas County: 28 %Eagle County: 23.2 %Elbert County: 22.1 %El Paso County: 24.5 %Fremont County: 16.3 %Garfield County: 25.7 %Gilpin County: 17.3 %Grand County: 18.2 %Gunnison County: 17.8 %Hinsdale County: 19.6 %Huerfano County: 16.3 %Jackson County: 16.5 %Jefferson County: 20.6 %Kiowa County: 22 %Kit Carson County: 23.9 %Lake County: 22 %La Plata County: 19.5 %Larimer County: 20.4 %Las Animas County: 18.4 %Lincoln County: 20.5 %Logan County: 18.9 %Mesa County: 22 %Mineral County: 14.2 %Moffat County: 25.5 %Montezuma County: 22.3 %Montrose County: 22.3 %Morgan County: 26.9 %Otero County: 23.7 %Ouray County: 16 %Park County: 16.7 %Phillips County: 24.2 %Pitkin County: 16.6 %Prowers County: 25.4 %Pueblo County: 23 %Rio Blanco County: 24.8 %Rio Grande County: 23.9 %Routt County: 19.9 %Saguache County: 22.1 %San Juan County: 14.1 %San Miguel County: 20.5 %Sedgwick County: 21.1 %Summit County: 16.8 %Teller County: 18 %Washington County: 23.2 %Weld County: 27.1 %Yuma County: 25.9 %
  • Under 17
  • 17 to 19
  • 19 to 21
  • 21 to 23
  • 23 to 25
  • 25 and over
%, 2016. Source: Invokely calculation with data from U.S. Census Bureau. Boundaries: U.S. Census Bureau cartographic boundary files.

Top 40 counties, 2016

Douglas County: 28 %Douglas County28Conejos County: 27.5 %Conejos County27.5Adams County: 27.4 %Adams County27.4Weld County: 27.1 %Weld County27.1Morgan County: 26.9 %Morgan County26.9Yuma County: 25.9 %Yuma County25.9Garfield County: 25.7 %Garfield County25.7Cheyenne County: 25.6 %Cheyenne County25.6Moffat County: 25.5 %Moffat County25.5Prowers County: 25.4 %Prowers County25.4Rio Blanco County: 24.8 %Rio Blanco County24.8El Paso County: 24.5 %El Paso County24.5Arapahoe County: 24.4 %Arapahoe County24.4Phillips County: 24.2 %Phillips County24.2Kit Carson County: 23.9 %Kit Carson County23.9Rio Grande County: 23.9 %Rio Grande County23.9Broomfield County: 23.8 %Broomfield County23.8Alamosa County: 23.8 %Alamosa County23.8Otero County: 23.7 %Otero County23.7Washington County: 23.2 %Washington County23.2Eagle County: 23.2 %Eagle County23.2Pueblo County: 23 %Pueblo County23Montrose County: 22.3 %Montrose County22.3Montezuma County: 22.3 %Montezuma County22.3Saguache County: 22.1 %Saguache County22.1Elbert County: 22.1 %Elbert County22.1Mesa County: 22 %Mesa County22Kiowa County: 22 %Kiowa County22Lake County: 22 %Lake County22Sedgwick County: 21.1 %Sedgwick County21.1Delta County: 20.6 %Delta County20.6Jefferson County: 20.6 %Jefferson County20.6Baca County: 20.5 %Baca County20.5Lincoln County: 20.5 %Lincoln County20.5San Miguel County: 20.5 %San Miguel County20.5Larimer County: 20.4 %Larimer County20.4Denver County: 20.3 %Denver County20.3Boulder County: 20 %Boulder County20Routt County: 19.9 %Routt County19.9Dolores County: 19.6 %Dolores County19.6Douglas County: 28 %Douglas County28Conejos County: 27.5 %Conejos County27.5Adams County: 27.4 %Adams County27.4Weld County: 27.1 %Weld County27.1Morgan County: 26.9 %Morgan County26.9Yuma County: 25.9 %Yuma County25.9Garfield County: 25.7 %Garfield County25.7Cheyenne County: 25.6 %Cheyenne County25.6Moffat County: 25.5 %Moffat County25.5Prowers County: 25.4 %Prowers County25.4Rio Blanco County: 24.8 %Rio Blanco County24.8El Paso County: 24.5 %El Paso County24.5Arapahoe County: 24.4 %Arapahoe County24.4Phillips County: 24.2 %Phillips County24.2Kit Carson County: 23.9 %Kit Carson County23.9Rio Grande County: 23.9 %Rio Grande County23.9Broomfield County: 23.8 %Broomfield County23.8Alamosa County: 23.8 %Alamosa County23.8Otero County: 23.7 %Otero County23.7Washington County: 23.2 %Washington County23.2Eagle County: 23.2 %Eagle County23.2Pueblo County: 23 %Pueblo County23Montrose County: 22.3 %Montrose County22.3Montezuma County: 22.3 %Montezuma County22.3Saguache County: 22.1 %Saguache County22.1Elbert County: 22.1 %Elbert County22.1Mesa County: 22 %Mesa County22Kiowa County: 22 %Kiowa County22Lake County: 22 %Lake County22Sedgwick County: 21.1 %Sedgwick County21.1Delta County: 20.6 %Delta County20.6Jefferson County: 20.6 %Jefferson County20.6Baca County: 20.5 %Baca County20.5Lincoln County: 20.5 %Lincoln County20.5San Miguel County: 20.5 %San Miguel County20.5Larimer County: 20.4 %Larimer County20.4Denver County: 20.3 %Denver County20.3Boulder County: 20 %Boulder County20Routt County: 19.9 %Routt County19.9Dolores County: 19.6 %Dolores County19.6
%. Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-12.

Full ranking

RankCounties2016 (%)Change on 2015
1Douglas County28-0.5 pts
2Conejos County27.5-0.6 pts
3Adams County27.4-0.3 pts
4Weld County27.1-0.2 pts
5Morgan County26.9-0.1 pts
6Yuma County25.9-0.2 pts
7Garfield County25.7-0.1 pts
8Cheyenne County25.6+0.3 pts
9Moffat County25.50 pts
10Prowers County25.4-0.1 pts
11Rio Blanco County24.8+0.1 pts
12El Paso County24.5-0.3 pts
13Arapahoe County24.4-0.2 pts
14Phillips County24.2+0.4 pts
15Kit Carson County23.9+1.4 pts
16Rio Grande County23.9+0.1 pts
17Broomfield County23.8-0.2 pts
18Alamosa County23.8-0.5 pts
19Otero County23.7+0.1 pts
20Washington County23.2+0.5 pts
21Eagle County23.2-0.2 pts
22Pueblo County23-0.2 pts
23Montrose County22.3-0.3 pts
24Montezuma County22.3-0 pts
25Saguache County22.1-0.2 pts
26Elbert County22.1-0.5 pts
27Mesa County22-0.2 pts
28Kiowa County22+0.3 pts
29Lake County22-0.4 pts
30Sedgwick County21.1+0.1 pts
31Delta County20.6-0.2 pts
32Jefferson County20.6-0.3 pts
33Baca County20.5-0.3 pts
34Lincoln County20.5+0.5 pts
35San Miguel County20.5+0.6 pts
36Larimer County20.4-0.2 pts
37Denver County20.3-0.3 pts
38Boulder County20-0.2 pts
39Routt County19.9+0.1 pts
40Dolores County19.6+0.5 pts
41Costilla County19.6+1.7 pts
42Hinsdale County19.6+1.5 pts
43La Plata County19.50 pts
44Logan County18.9-0.3 pts
45Archuleta County18.7+0.2 pts
46Las Animas County18.4-0.1 pts
47Grand County18.2+0.2 pts
48Teller County18-0.4 pts
49Gunnison County17.8-0 pts
50Gilpin County17.3-0.3 pts
51Summit County16.8+0.3 pts
52Park County16.7-0.2 pts
53Pitkin County16.60 pts
54Jackson County16.5-0.6 pts
55Huerfano County16.3+0.4 pts
56Fremont County16.30 pts
57Clear Creek County16.3+0.1 pts
58Ouray County16-0.7 pts
59Chaffee County15.5+0.1 pts
60Bent County15.4-0.3 pts
61Custer County15+0.1 pts
62Mineral County14.2+0.3 pts
63San Juan County14.1-0.7 pts
64Crowley County13+1.2 pts

Other periods

About this ranking

Residents aged 0 to 17 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.

Uses the US age of majority. Not comparable with population_0_14_share, which stops at 14.

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 0 to 17 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 0 to 17 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 under 18, 2016) [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 0 to 17 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 under 18, 2016. U.S. Census Bureau, 25 June 2026, https://www.census.gov/programs-surveys/popest/data/data-sets.html. Invokely, https://invokely.ai/rankings/population-under-18/colorado-counties?period=2016. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Census Bureau. 2026. Population Estimates Program, county population by age and sex: residents aged 0 to 17 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 under 18, 2016. 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-under-18/colorado-counties?period=2016.

Harvard

U.S. Census Bureau (2026) Population Estimates Program, county population by age and sex: residents aged 0 to 17 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 under 18, 2016 [Dataset]. Available at: https://www.census.gov/programs-surveys/popest/data/data-sets.html, via Invokely: https://invokely.ai/rankings/population-under-18/colorado-counties?period=2016 (Accessed: 12 October 2026).

BibTeX
@misc{census_counties_in_colorado_by_2016,
  author = {{U.S. Census Bureau}},
  title = {{Population Estimates Program, county population by age and sex: residents aged 0 to 17 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 under 18, 2016}},
  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-under-18/colorado-counties?period=2016. Publisher attribution: U.S. Census Bureau. Population Estimates Program, county population by age and sex: residents aged 0 to 17 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 0 to 17 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 under 18, 2016
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-under-18/colorado-counties?period=2016
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/population-under-18/colorado-counties?period=2016.
N1  - Publisher attribution: U.S. Census Bureau. Population Estimates Program, county population by age and sex: residents aged 0 to 17 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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Rank Counties in Colorado by population under 18 using official data, and cite the source.
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Questions

Which county has the highest population under 18?

Douglas County, with 28% in 2016, according to the U.S. Census Bureau.

Which county has the lowest population under 18?

Crowley County, with 13% in 2016.

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 0 to 17 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 under 18: other rankings

Counties in Colorado: more rankings