Counties in Colorado by median age on 1 July (US county estimates)

Custer County had the highest median age on 1 July (US county estimates) of 64 counties in 2017, at 57.1 years. Adams County had the lowest, at 33.8 years. The median was 41 years. Source: the U.S. Census Bureau.

Keep it in a collection in your library.
Highest57.1Custer County
Lowest33.8Adams County
Median4164 counties

Map of counties, 2017

Adams County: 33.8 yearsAlamosa County: 34.1 yearsArapahoe County: 36.2 yearsArchuleta County: 50.9 yearsBaca County: 47.2 yearsBent County: 41.1 yearsBoulder County: 36.7 yearsBroomfield County: 37.4 yearsChaffee County: 49.1 yearsCheyenne County: 41.9 yearsClear Creek County: 47.9 yearsConejos County: 39.9 yearsCostilla County: 52 yearsCrowley County: 40.4 yearsCuster County: 57.1 yearsDelta County: 48.5 yearsDenver County: 34 yearsDolores County: 48.9 yearsDouglas County: 38.5 yearsEagle County: 36.6 yearsElbert County: 46.1 yearsEl Paso County: 34.5 yearsFremont County: 45.5 yearsGarfield County: 36.5 yearsGilpin County: 47.1 yearsGrand County: 43.9 yearsGunnison County: 36 yearsHinsdale County: 54.7 yearsHuerfano County: 56.1 yearsJackson County: 49.5 yearsJefferson County: 40.3 yearsKiowa County: 44.3 yearsKit Carson County: 39.6 yearsLake County: 36.1 yearsLa Plata County: 40.3 yearsLarimer County: 36.6 yearsLas Animas County: 47 yearsLincoln County: 39.6 yearsLogan County: 38.9 yearsMesa County: 39.6 yearsMineral County: 56.1 yearsMoffat County: 37.7 yearsMontezuma County: 44.6 yearsMontrose County: 44.6 yearsMorgan County: 36.7 yearsOtero County: 40.9 yearsOuray County: 53 yearsPark County: 49.7 yearsPhillips County: 41.8 yearsPitkin County: 43 yearsProwers County: 37.8 yearsPueblo County: 40.2 yearsRio Blanco County: 38 yearsRio Grande County: 42.1 yearsRoutt County: 40.3 yearsSaguache County: 46.8 yearsSan Juan County: 48.3 yearsSan Miguel County: 40.8 yearsSedgwick County: 48.7 yearsSummit County: 37.7 yearsTeller County: 50.9 yearsWashington County: 42.6 yearsWeld County: 34 yearsYuma County: 38.3 years
  • Under 37
  • 37 to 40
  • 40 to 41
  • 41 to 46
  • 46 to 49
  • 49 and over
years, 2017. Source: U.S. Census Bureau, Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage. Boundaries: U.S. Census Bureau cartographic boundary files.

Top 40 counties, 2017

Custer County: 57.1 yearsCuster County57.1Huerfano County: 56.1 yearsHuerfano County56.1Mineral County: 56.1 yearsMineral County56.1Hinsdale County: 54.7 yearsHinsdale County54.7Ouray County: 53 yearsOuray County53Costilla County: 52 yearsCostilla County52Archuleta County: 50.9 yearsArchuleta County50.9Teller County: 50.9 yearsTeller County50.9Park County: 49.7 yearsPark County49.7Jackson County: 49.5 yearsJackson County49.5Chaffee County: 49.1 yearsChaffee County49.1Dolores County: 48.9 yearsDolores County48.9Sedgwick County: 48.7 yearsSedgwick County48.7Delta County: 48.5 yearsDelta County48.5San Juan County: 48.3 yearsSan Juan County48.3Clear Creek County: 47.9 yearsClear Creek County47.9Baca County: 47.2 yearsBaca County47.2Gilpin County: 47.1 yearsGilpin County47.1Las Animas County: 47 yearsLas Animas County47Saguache County: 46.8 yearsSaguache County46.8Elbert County: 46.1 yearsElbert County46.1Fremont County: 45.5 yearsFremont County45.5Montezuma County: 44.6 yearsMontezuma County44.6Montrose County: 44.6 yearsMontrose County44.6Kiowa County: 44.3 yearsKiowa County44.3Grand County: 43.9 yearsGrand County43.9Pitkin County: 43 yearsPitkin County43Washington County: 42.6 yearsWashington County42.6Rio Grande County: 42.1 yearsRio Grande County42.1Cheyenne County: 41.9 yearsCheyenne County41.9Phillips County: 41.8 yearsPhillips County41.8Bent County: 41.1 yearsBent County41.1Otero County: 40.9 yearsOtero County40.9San Miguel County: 40.8 yearsSan Miguel County40.8Crowley County: 40.4 yearsCrowley County40.4Jefferson County: 40.3 yearsJefferson County40.3La Plata County: 40.3 yearsLa Plata County40.3Routt County: 40.3 yearsRoutt County40.3Pueblo County: 40.2 yearsPueblo County40.2Conejos County: 39.9 yearsConejos County39.9Custer County: 57.1 yearsCuster County57.1Huerfano County: 56.1 yearsHuerfano County56.1Mineral County: 56.1 yearsMineral County56.1Hinsdale County: 54.7 yearsHinsdale County54.7Ouray County: 53 yearsOuray County53Costilla County: 52 yearsCostilla County52Archuleta County: 50.9 yearsArchuleta County50.9Teller County: 50.9 yearsTeller County50.9Park County: 49.7 yearsPark County49.7Jackson County: 49.5 yearsJackson County49.5Chaffee County: 49.1 yearsChaffee County49.1Dolores County: 48.9 yearsDolores County48.9Sedgwick County: 48.7 yearsSedgwick County48.7Delta County: 48.5 yearsDelta County48.5San Juan County: 48.3 yearsSan Juan County48.3Clear Creek County: 47.9 yearsClear Creek County47.9Baca County: 47.2 yearsBaca County47.2Gilpin County: 47.1 yearsGilpin County47.1Las Animas County: 47 yearsLas Animas County47Saguache County: 46.8 yearsSaguache County46.8Elbert County: 46.1 yearsElbert County46.1Fremont County: 45.5 yearsFremont County45.5Montezuma County: 44.6 yearsMontezuma County44.6Montrose County: 44.6 yearsMontrose County44.6Kiowa County: 44.3 yearsKiowa County44.3Grand County: 43.9 yearsGrand County43.9Pitkin County: 43 yearsPitkin County43Washington County: 42.6 yearsWashington County42.6Rio Grande County: 42.1 yearsRio Grande County42.1Cheyenne County: 41.9 yearsCheyenne County41.9Phillips County: 41.8 yearsPhillips County41.8Bent County: 41.1 yearsBent County41.1Otero County: 40.9 yearsOtero County40.9San Miguel County: 40.8 yearsSan Miguel County40.8Crowley County: 40.4 yearsCrowley County40.4Jefferson County: 40.3 yearsJefferson County40.3La Plata County: 40.3 yearsLa Plata County40.3Routt County: 40.3 yearsRoutt County40.3Pueblo County: 40.2 yearsPueblo County40.2Conejos County: 39.9 yearsConejos County39.9
years. Source: U.S. Census Bureau, Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage. Retrieved 2026-10-12.

Full ranking

RankCounties2017
years
Change on 2016
1Custer County57.1-0.1
2Huerfano County56.1+0.6
2Mineral County56.1-0.1
4Hinsdale County54.7+0.6
5Ouray County530
6Costilla County52+1
7Archuleta County50.9-0.2
7Teller County50.9+0.4
9Park County49.7+0.2
10Jackson County49.5+1
11Chaffee County49.1+0.1
12Dolores County48.9+0.4
13Sedgwick County48.7+2
14Delta County48.5+0.6
15San Juan County48.3+1.7
16Clear Creek County47.90
17Baca County47.2-0.6
18Gilpin County47.1-0.1
19Las Animas County47+0.3
20Saguache County46.8-0.3
21Elbert County46.1-0.1
22Fremont County45.50
23Montezuma County44.6+0.2
23Montrose County44.6-0.1
25Kiowa County44.3-1.5
26Grand County43.9+0.3
27Pitkin County43-0.1
28Washington County42.6-0.1
29Rio Grande County42.1+0.2
30Cheyenne County41.9-0.1
31Phillips County41.8-0.2
32Bent County41.10
33Otero County40.9+0.1
34San Miguel County40.8+0.3
35Crowley County40.4-0.4
36Jefferson County40.3-0.1
36La Plata County40.3+0.3
36Routt County40.3+0.1
39Pueblo County40.2+0.2
40Conejos County39.9-0.2
41Kit Carson County39.6+0.3
41Lincoln County39.6+0.3
41Mesa County39.6+0.3
44Logan County38.9+0.2
45Douglas County38.5+0.2
46Yuma County38.30
47Rio Blanco County38+0.6
48Prowers County37.80
49Moffat County37.7+0.1
49Summit County37.7+0.3
51Broomfield County37.4-0.1
52Boulder County36.7+0.3
52Morgan County36.7+0.3
54Eagle County36.6+0.2
54Larimer County36.6+0.3
56Garfield County36.5+0.3
57Arapahoe County36.2+0.1
58Lake County36.1-0.2
59Gunnison County36+0.4
60El Paso County34.5+0.2
61Alamosa County34.1+0.6
62Denver County34+0.1
62Weld County34+0.1
64Adams County33.8+0.3

Other periods

About this ranking

Age that divides the resident population of a US county into two halves of equal size on 1 July, from Census Bureau population estimates calculated by single year of age.

Counties only: the county file has no state or national medians, and medians cannot be added up. A single-year estimate, unlike median_age, which for US places is a five-year American Community Survey estimate.

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: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage. 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: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage (Counties in Colorado by median age on 1 July (US county estimates), 2017) [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: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage, Counties in Colorado by median age on 1 July (US county estimates), 2017. U.S. Census Bureau, 25 June 2026, https://www.census.gov/programs-surveys/popest/data/data-sets.html. Invokely, https://invokely.ai/rankings/median-age-july-1-us-counties/colorado-counties?period=2017. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Census Bureau. 2026. Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage. Counties in Colorado by median age on 1 July (US county estimates), 2017. Dataset. Accessed October 12, 2026. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Also distributed by Invokely, https://invokely.ai/rankings/median-age-july-1-us-counties/colorado-counties?period=2017.

Harvard

U.S. Census Bureau (2026) Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage, Counties in Colorado by median age on 1 July (US county estimates), 2017 [Dataset]. Available at: https://www.census.gov/programs-surveys/popest/data/data-sets.html, via Invokely: https://invokely.ai/rankings/median-age-july-1-us-counties/colorado-counties?period=2017 (Accessed: 12 October 2026).

BibTeX
@misc{census_counties_in_colorado_by_2017,
  author = {{U.S. Census Bureau}},
  title = {{Population Estimates Program, county population by age and sex: median age (MEDIAN\_AGE\_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage: Counties in Colorado by median age on 1 July (US county estimates), 2017}},
  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/median-age-july-1-us-counties/colorado-counties?period=2017. Publisher attribution: U.S. Census Bureau. Population Estimates Program, county population by age and sex: median age (MEDIAN\_AGE\_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage. 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: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage: Counties in Colorado by median age on 1 July (US county estimates), 2017
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/median-age-july-1-us-counties/colorado-counties?period=2017
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/median-age-july-1-us-counties/colorado-counties?period=2017.
N1  - Publisher attribution: U.S. Census Bureau. Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage. 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 median age on 1 July (US county estimates)?

Custer County, with 57.1 years in 2017, according to the U.S. Census Bureau.

Which county has the lowest median age on 1 July (US county estimates)?

Adams County, with 33.8 years in 2017.

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: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage. Retrieved 2026-10-12.

Median age on 1 July (US county estimates): other rankings

Counties in Colorado: more rankings