# Counties in Colorado by population aged 18 to 64, 2025

All 64 values come from U.S. Census Bureau for 2025, so the places are comparable.

- Indicator id: `population_18_64_share`
- Unit: %
- Definition: 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.
- Source: 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: 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.
- Web page: https://invokely.ai/rankings/population-18-64/colorado-counties

| Rank | Place | % |
|---:|---|---:|
| 1 | Crowley County | 71.4 |
| 2 | Denver County | 68.9 |
| 3 | Summit County | 68.3 |
| 4 | San Juan County | 68 |
| 5 | Gunnison County | 68 |
| 6 | San Miguel County | 65.7 |
| 7 | Eagle County | 65.6 |
| 8 | Bent County | 65.4 |
| 9 | Lake County | 65 |
| 10 | Boulder County | 64.9 |
| 11 | Gilpin County | 64.6 |
| 12 | Broomfield County | 64.2 |
| 13 | Adams County | 64.1 |
| 14 | Grand County | 63.3 |
| 15 | Larimer County | 62.8 |
| 16 | Jefferson County | 62.6 |
| 17 | Arapahoe County | 62.3 |
| 18 | Pitkin County | 62.2 |
| 19 | Routt County | 62.1 |
| 20 | El Paso County | 62 |
| 21 | Douglas County | 61.8 |
| 22 | Weld County | 61.1 |
| 23 | Clear Creek County | 60.9 |
| 24 | Garfield County | 60.9 |
| 25 | Lincoln County | 60.6 |
| 26 | Logan County | 60.2 |
| 27 | Fremont County | 59.6 |
| 28 | La Plata County | 59.4 |
| 29 | Park County | 59.3 |
| 30 | Alamosa County | 59.1 |
| 31 | Elbert County | 58.1 |
| 32 | Moffat County | 57.7 |
| 33 | Dolores County | 57.5 |
| 34 | Mesa County | 57.5 |
| 35 | Chaffee County | 57.3 |
| 36 | Pueblo County | 57.2 |
| 37 | Rio Blanco County | 56.5 |
| 38 | Morgan County | 55.8 |
| 39 | Teller County | 55.7 |
| 40 | Prowers County | 55.1 |
| 41 | Las Animas County | 54.5 |
| 42 | Otero County | 54.1 |
| 43 | Saguache County | 54 |
| 44 | Kit Carson County | 54 |
| 45 | Rio Grande County | 53.9 |
| 46 | Montezuma County | 53.3 |
| 47 | Montrose County | 53.3 |
| 48 | Phillips County | 53.3 |
| 49 | Jackson County | 53.2 |
| 50 | Yuma County | 53.2 |
| 51 | Washington County | 53.1 |
| 52 | Ouray County | 52.1 |
| 53 | Archuleta County | 51.7 |
| 54 | Baca County | 51.6 |
| 55 | Delta County | 51.4 |
| 56 | Mineral County | 51 |
| 57 | Cheyenne County | 50.8 |
| 58 | Conejos County | 50.8 |
| 59 | Costilla County | 50.3 |
| 60 | Huerfano County | 49.4 |
| 61 | Sedgwick County | 49.3 |
| 62 | Kiowa County | 48.5 |
| 63 | Custer County | 47.8 |
| 64 | Hinsdale County | 46.5 |