Colorado Citizen Population By County in 2021 (ACS-5Yrs)

Updated on March 28, 2026.

Based on the US Census Bureau's special tabulation from the ACS 5-year estimates, in 2021, the citizen population for Colorado was 5,432,775 and represented 94.93% of the total Colorado population.

Among all Colorado counties, El Paso had the highest citizen population (702.46K), followed by Denver (651.41K), and Arapahoe (598.82K).

In terms of percentages, Mineral had the highest percentage of its population being citizens (100.00%), followed by Kiowa (99.65%), and Park (99.45%).

The chart and table below shows the citizen population of each county and the percentage of each county's population that were citizens.

You can see similar information for other states and by state for the United States.

See this for other years:
Colorado Citizen Population By County in 2021
Colorado Citizen Population By County in 2021
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County Citizen Population % of County Population
El Paso 702460 97.20
Denver 651410 92.16
Arapahoe 598820 91.90
Jefferson 563825 97.19
Adams 467170 90.72
Larimer 343915 96.97
Douglas 339820 96.56
Boulder 311615 94.80
Weld 305180 94.65
Pueblo 164340 98.14
Mesa 151305 97.82
Broomfield 69600 95.74
Garfield 55655 90.91
La Plata 54965 98.73
Eagle 50345 90.39
Fremont 48355 98.67
Montrose 40650 96.03
Delta 30385 97.59
Summit 29530 95.14
Morgan 26220 90.82
Elbert 25540 98.63
Montezuma 25325 97.72
Routt 24395 97.97
Teller 24390 99.13
Logan 21130 97.08
Chaffee 19020 97.87
Otero 18440 98.80
Park 17290 99.45
Pitkin 16780 96.05
Gunnison 16585 98.43
Alamosa 15650 95.57
Grand 15190 97.19
Las Animas 14105 97.08
Archuleta 13030 98.23
Moffat 12770 96.45
Prowers 11285 94.32
Rio Grande 11070 96.47
Clear Creek 9275 98.41
Yuma 8680 87.28
San Miguel 7750 95.86
Conejos 7455 98.35
Kit Carson 6835 96.68
Lake 6745 90.96
Huerfano 6725 99.12
Rio Blanco 6270 96.54
Saguache 6250 98.12
Crowley 5955 98.92
Bent 5760 98.29
Gilpin 5625 96.82
Lincoln 5425 96.36
Ouray 4810 99.18
Washington 4735 97.93
Custer 4675 99.05
Phillips 4085 90.88
Baca 3430 97.44
Costilla 3395 96.59
Sedgwick 2360 95.94
Dolores 2270 99.13
Cheyenne 1635 96.75
Kiowa 1410 99.65
Jackson 1365 99.27
Hinsdale 855 99.42
Mineral 795 100.00
San Juan 650 92.86