Colorado Counties by Population (2026)

2026 Pop.

100K

200K

300K

400K

500K

600K

700K

Top 5 Most Populous Counties

64 Counties

County
2026 Pop. ↓
Area (mi²)
Density
Change (2020)
El Paso County764,4482.1K3604.18%
Denver County744,3231534,8653.72%
Arapahoe County677,0267988483.31%
Jefferson County580,213764759-0.51%
Adams County557,5651.2K4787.12%
Douglas County411,70384149014.26%
Weld County388,8034K9817.3%
Larimer County380,6622.6K1475.76%
Boulder County333,9487264600.9%
Pueblo County170,1522.4K711.07%
Mesa County164,4003.3K495.38%
Broomfield County80,911332,4528.61%
Garfield County63,6592.9K223%
La Plata County57,6671.7K343.58%
Eagle County53,8061.7K32-3.34%
Fremont County49,5751.5K321.4%
Montrose County45,7802.2K206.91%
Delta County33,1251.1K296.66%
Morgan County31,2881.3K247.59%
Summit County30,99860851-0.77%
Elbert County30,5221.9K1616.47%
Montezuma County27,3232K135.54%
Routt County25,4212.4K112.34%
Teller County25,164557451.69%
Chaffee County21,1241K218.39%
Logan County20,9451.8K11-1.24%
Park County18,7062.2K97.38%
Otero County17,6771.3K14-5.29%
Gunnison County17,2623.2K51.86%
Alamosa County16,731723232.17%
Pitkin County16,54997117-4.7%
Grand County16,5201.8K94.91%
Las Animas County14,7664.8K31.83%
Archuleta County14,0021.4K104.3%
Moffat County12,8524.7K3-3.14%
Prowers County12,2931.6K82.27%
Rio Grande County11,00891212-4.63%
Yuma County10,1822.4K42.13%
Clear Creek County8,98239523-4.04%
San Miguel County7,7091.3K6-4.28%
Conejos County7,6251.3K62.34%
Lake County7,37337720-0.54%
Kit Carson County7,1762.2K31.6%
Huerfano County6,8821.6K40.85%
Rio Blanco County6,6493.2K21.96%
Saguache County6,6363.2K23.77%
Gilpin County6,043150403.89%
Bent County5,9131.5K47.9%
Lincoln County5,7982.6K22.42%
Crowley County5,5687877-2.06%
Custer County5,557739817.61%
Ouray County5,221541106.94%
Washington County4,5952.5K2-4.55%
Phillips County4,4846887-1.04%
Costilla County3,8101.2K38.83%
Baca County3,3752.6K1-3.07%
Dolores County2,3511.1K20.86%
Sedgwick County2,1615484-9.54%
Cheyenne County1,6601.8K1-4.93%
Kiowa County1,4241.8K1-1.93%
Jackson County1,1871.6K1-13.86%
Mineral County93587617.35%
San Juan County869388222.74%
Hinsdale County7191.1K1-8.64%

Overview of Colorado Counties

There are 64 counties in Colorado.

El Paso County is the largest county in the state, with a population of 764,448. The most recent census shows that its population has increased by 0.04% since the previous census.

A number of other Colorado counties also boast relatively large populations for their state, though not able to match the density of El Paso County:

Colorado Counties with the Fewest Residents

The smallest county in Colorado is Hinsdale County , with a population of just 719. This total represents a decrease of 0.1% since the last census count was performed.

Other small counties include:

Colorado Counties with Rapid Growth

San Juan County , with its current population of 869, has shown the largest population growth, with an increase of 0.2% since the last census.

Adams County has also had relatively high population growth of 0.07% with 557,565 residents.

On the other hand, Jackson County has had the largest decrease in population, with its 1,187 current residents totalling 0.1% less than the previous census.

Sources

  1. US Census State Population Estimates - Most recent state estimates from the Census Bureau's Population Estimates Program
  2. US Census County Population Estimates - Most recent county estimates from the Census Bureau's Population Estimates Program
  3. American Community Survey (2009 - 2013)
  4. Census QuickFacts
  5. Historical Populations of States and Counties (1790 - 1990)

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