Colorado Counties

Colorado Counties, That is the content of today’s article. Colorado has 64 Counties. It started off at first with only 17 and kept on growing until it got to 26 on the 1st of August, 1861, when Colorado became a state. Later on, more Counties were created from each of the already existing ones making the number increase.


Today, we have 64 Counties in Colorado showing that 38 Counties after Colorado became a state in 1861. Looking at this content you will observe that during the formation of the counties, 2-4 counties are created on the same day making it possible for Colorado to have a total number of 64 counties in a short period of time.

Below is a list of Colorado Counties arranged in alphabetical order with their Year of Creation, County Seat, Population, and Area.

Table of Contents

64 A – Z Lists of Colorado Counties, Year Formed, Population, County Seat, and Area

Adams County

Amusement, Carousel, Amusement Park


County Seat: Brighton 1902-11-15

Population: 519,572

Area: 1,182.29 sq mi

Alamosa County

Potato Field, Aroostook County

Formed: 1913-03-08

County Seat: Alamosa

Population: 16,376

Area: 723.21 sq mi

Arapahoe County

House, Roof, Blue, Country, County, Home

Formed: 1861-11-01

County Seat: Littleton 

Population: 655,070 

Area:804.41 sq mi

Archuleta County

Mount St Helens, Volcanic Eruption

Formed: 1885-04-14

County Seat: Pagosa Springs 

Population: 13,359 

Area: 1,354.53 sq mi

Baca County

Village, Agriculture, Valley, Vietnam

Formed: 1889-04-16

County Seat: Springfield 

Population: 3,506 

Area: 2,558.48 sq mi

Bent County

Agriculture, Green, Rice, Asia, Bali

Formed: 1870-02-11

County Seat: Las Animas

Population: 5,650

Area: 1,541.07 sq mi

Boulder County

Sunset, Dawn, Nature, Dusk, Sun, Sky

Formed: 1861-11-01

County Seat: Boulder 

Population: 330,758 

Area:740.48 sq mi

City and County of Broomfield

Mansion, England, Estate, Country House

Formed: 2001-11-15

County Seat: Broomfield 

Population: 74,112

Area: 33.57 sq mi

Chaffee County

Carnival Rides, Night, Ferris Wheel

Formed: 1879-02-10

County Seat: Salida 

Population: 19,476

Area: 1,014.12 sq mi

Cheyenne County

Farm Yard, Farm, Nature, Farmhouse, Fall

Formed: 1889-03-25

County Seat: Cheyenne Wells 

Population: 1,748 

Area: 1,781.90 sq mi

Clear Creek County

Mansion, England, Estate, Country House

Formed: 1861-11-01

County Seat: Georgetown

Population: 9,397

Area: 396.53 sq mi

Conejos County

Agriculture, Asia, Go Back, Black


County Seat: Conejos 


Area: 1,290.22 sq mi

Costilla County

Carnival, Summer, Ferris Wheel, Holiday


County Seat: San Luis 

Population: 3,499 

Area: 1,229.38 sq mi

Crowley County

Agriculture, Asia, Bali, Cambodia, China


County Seat: Ordway

Population: 5,922 

Area: 800.27 sq mi

Custer County

Barn, Rustic, Barns, Ohio, Digital Art

Formed: 1877-03-09

County Seat: Westcliffe

Population: 4,704

Area: 739.24 sq mi

Delta County

Ireland, Forest, Nature, Green, Irish

Formed: 1883-02-11

County Seat: Delta 

Population: 31,196 

Area: 1,149.44 sq mi 

City and County of Denver

Sunset, Dawn, Nature, Dusk, Sun, Heaven

Formed: 1883-02-11

County Seat: Delta 

Population: 31,196 

Area: 1,149.44 sq mi 

Dolores County

Landscape, Ireland, Killarney

Formed: 1881-03-04

County Seat: Dove Creek

Population: 2,326

Area: 1,076.93 sq mi

Douglas County

Barn, Rustic, Barns, Ohio, Digital Art

Formed: 1861-11-01

County Seat: Castle Rock

Population: 357,978 

Area: 842.30 sq mi

Eagle County

Mount Shuksan, Mountain, Landscape

Formed: 1861-02-01

County Seat: Eagle 

Population: 55,731 

Area: 1,700.76 sq mi

El Paso County

Path, Wooden Track, Wooden Plank Path

Formed: 1861-11-01

County Seat: Colorado Springs 


Area: 2,128.60 sq mi

Elbert County

Yorkshire Rose, County, England

Formed: 1874-02-02

County Seat: Kiowa

Population: 26,062

Area: 1,849.08 sq mi

Fremont County

Usa, America, North America, Moose

Formed: 1861-11-01

County Seat: Cañon City 

Population: 48,939

Area: 1,533.09 sq mi

Garfield County

Gas Station, Workshop, Garage, Old

Formed: 1883-02-10

County Seat: Glenwood Springs

Population: 61,685

Area: 2,958.23 sq mi

Gilpin County

Montana, Barn, Landscape, Scenic, Hdr

Formed: 1861-11-01

County Seat: Central City

Population: 5,808

Area: 150.15 sq mi

Grand County

Park, Parklandschaft, English Garden

Formed: 1874-02-02

County Seat: Hot Sulphur Springs

Population: 15,717

Area: 1,868.53 sq mi

Gunnison County

Religion, Grave Facility, Brown Hill

Formed: 1877-03-09

County Seat: Gunnison

Population: 16,918

Area: 3,259.22 sq mi

Hinsdale County

Tomb, Portal, Dolmen, Stone, Burial

Formed: 1874-02-10

County Seat: Lake City

Population: 788

Area: 1,123.35 sq mi

Huerfano County

Mount Edgcumbe House, Mansion

Formed: 1861-11-01

County Seat: Walsenburg

Population: 6,820

Area: 1,592.37 sq mi

Jackson County

Quilt, Storm, Storm Clouds, Sun

Formed: 1909-05-05

County Seat: Walden 

Population: 1,379

Area: 1,619.75 sq mi

Jefferson County

Mansion, Villa, House, Architecture

Formed: 1861-11-01

County Seat: Golden

Population: 582,910

Area: 772.85 sq mi

Kiowa County

Mansion, Villa, House, Architecture

Formed: 1889-04-11

County Seat: Eads

Population: 1,446

Area: 1,785.90 sq mi

Kit Carson County

Barn, Rustic, Barns, Ohio, Digital Art

Formed: 1889-04-11

County Seat: Burlington 

Population: 7,087

Area: 2,162.43 sq mi

La Plata County

Giants Causeway, Northern Ireland

Formed: 1874-02-10

County Seat: Durango

Population: 55,638

Area: 1,700.44 sq mi

Lake County

Outdoor, Forest, Foliage, Park, Green

Formed: 1861-11-01

County Seat: Leadville 

Population: 7,436

Area: 383.55 sq mi

Larimer County

Mount St Helens, Volcano, Mountain

Formed: 1861-11-01

County Seat: Fort Collins 

Population: 359,066

Area: 2,631.75 sq mi

Las Animas County

Mount Edgcumbe House, Mansion, Towers

Formed: 1866-02-09

County Seat: Trinidad

Population: 14,555

Area: 4,773.27 sq mi

Lincoln County

Quilt, Quilt Barn, Windmill, Barn

Formed: 1889-04-11

County Seat: Hugo

Population: 5,675

Area: 2,585.21 sq mi

Logan County

Two Track, Lane, Scenery, Trees

Formed: 1887-02-25

County Seat: Sterling

Population: 21,528 

Area: 1,845.31 sq mi

Mesa County

Barn, Rustic, Barns, Swing, Broken Swing

Formed: 1883-02-14

County Seat: Grand Junction

Population: 155,703 

Area: 3,345.69 sq mi

Mineral County

Winter, City, Snow, Hungary, Building


County Seat: Creede

Population: 865

Area: 878.16 sq mi

Moffat County

Away, Ireland, Abandoned

Formed: 1911-02-27

County Seat: Craig

Population: 13,292 

Area: 4,755.86 sq mi

Montezuma County

Doc Ryburns House, Bannack, State, Park

Formed: 1889-04-16

County Seat: Cortez

Population: 25,849 

Area: 2,035.80 sq mi

Montrose County

Rock, Insight, Canyon, Outlook


County Seat: Montrose

Population: 42,679

Area: 2,246.43 sq mi

Morgan County

Rock, Insight, Canyon, Outlook

Formed: 1889-02-19

County Seat: Fort Morgan

Population: 29,111

Area: 1,293.83 sq mi

Otero County

Rock, Insight, Canyon, Outlook

Formed: 1889-03-25

County Seat: La Junta


Area: 1,267.66 sq mi

Ouray County

Pinwheels, Energy, Wind Power

Formed: 1877-01-18

County Seat: Ouray 

Population: 4,874 

Area: 542.30 sq mi

Park County

Camping Tipi, Campground, Tent, Tipi

Formed: 1861-11-01

County Seat: Fairplay 

Population: 17,390 

Area: 2,209.36 sq mi

Phillips County

Scenery, Sunrise, Trees, Autumn, Bird

Formed: 1889-03-27

County Seat: Holyoke 

Population: 4,530

Area: 688.30 sq mi

Pitkin County

Scenery, Sunrise, Trees, Autumn, Bird

Formed: 1881-02-23

County Seat: Aspen 

Population: 17,358

Area: 970.37 sq mi

Prowers County

Barn, Rustic, Barns, Ohio, Digital Art

Formed: 1889-04-11

County Seat: Lamar 

Population: 11,999 

Area: 1,645.37 sq mi

Pueblo County

Pingyuan County, Guangdong

Formed: 1861-11-01

County Seat:Pueblo 

Population: 168,162

Area: 2,396.77 sq mi

Rio Blanco County

Pingyuan County, Guangdong

Formed: 1889-03-25

County Seat: Meeker  

Population: 6,529 

Area: 3,226.24 sq mi

Rio Grande County

River, Rapids, Canyon, Water, Nature

Formed: 1874-02-10

County Seat: Del Norte 

Population: 11,539 

Area: 913.10 sq mi

Routt County

Barn, Rustic, Barns, Morning, Dawn


County Seat: Steamboat Springs 

Population: 24,829

Area: 2,362.11 sq mi

Saguache County

Barn, Rustic, Barns, Morning, Dawn

Formed: 1866-12-29

County Seat: Saguache 

Population: 6,368 

Area: 3,168.32 sq mi

San Juan County

Barn, Rustic, Barns, Morning, Dawn

Formed: 1876-01-31

County Seat: Silverton


Area: 388.99 sq mi

San Miguel County

Breakthrough, Cliff, Cliffs, Sea, Water

Formed: 1883-03-02

County Seat: Telluride 1883-03-02

Population: 8,072

Area: 1,290.76 sq mi

Sedgwick County

Farm Market Beans, Beans, Green, Dane

Formed: 1883-03-02

County Seat: Telluride 1883-03-02


Area: 548.83 sq mi

Summit County

Scenery, 3D, Trees, Artistic, Art Print

Formed: 1861-11-01

County Seat: Breckenridge

Population: 31,055 

Area: 618.92 sq mi

Teller County

Train, Railroad, Rails, Train Ride

Formed: 1899-03-23

County Seat: Cripple Creek

Population: 24,710

Area: 558.58 sq mi

Washington County

Summer, Virginia, Northern Virginia

Formed: 1887-02-09

County Seat: kron 

Population: 4,817

Area:2,522.90 sq mi

Weld County

Summer, Virginia, Northern Virginia

Formed: 1861-11-01

County Seat: Greeley 

Population: 328,981

Area: 4,013.84 sq mi

Yuma County

Sunset, Weeds, Warm, Glow, Green

Formed: 1889-03-15

County Seat: Wray 1889-03-15

Population: 9,988 

Area: 2,369.61 sq mi


There are currently 64 counties in the U.S. State of Colorado but before Colorado became a U.S. state in 1876, it had only 26 counties. The number rose to 40 in 1885 after the creation of Archuleta County and eventually to 64 counties in 2001 when Broomfield was consolidated as a city and county.

These Colorado counties are important units of government in the state because there’re no townships or other minor civil divisions.

Out of these 64 counties, two (Broomfield and Denver) have consolidated city and county governments. Each county in Colorado has its own character and sense of identity.

Here is a list of all the counties in Colorado, their FIPS code, year formed, and population.

List of all Colorado Counties

County Name County Seat FIPS Code Year Formed Population as of 2019
Adams County Brighton 001 1902 517,421
Alamosa County Alamosa 003 1913 16,107
Arapahoe County Littleton 005 1861 656,590
Archuleta County Pagosa Springs 007 1885 13,253
Baca County Springfield 009 1889 3,561
Bent County Las Animas 011 1870 5,787
Boulder County Boulder 013 1861 326,196
Broomfield County Broomfield 014 2001 67,886
Chaffee County Salida 015 1879 19,557
Cheyenne County Cheyenne Wells 017 1889 2,026
Clear Creek County Georgetown 019 1861 9,700
Conejos County Conejos 021 1861 8,128
Costilla County San Luis 023 1861 3,745
Crowley County Ordway 025 1911 5,754
Custer County Westcliffe 027 1877 4,776
Delta County Delta 029 1883 30,565
Denver County Denver 031 1902 735,538
Dolores County Dove Creek 033 1881 1,857
Douglas County Castle Rock 035 1861 351,154
Eagle County Eagle 037 1883 55,127
El Paso County Colorado Springs 041 1861 720,403
Elbert County Kiowa 039 1874 26,729
Fremont County Cañon City 043 1861 47,839
Garfield County Glenwood Springs 045 1883 60,061
Gilpin County Central City 047 1861 6,243
Grand County Hot Sulphur Springs 049 1874 15,303
Gunnison County Gunnison 051 1877 16,802
Hinsdale County Lake City 053 1874 857
Huerfano County Walsenburg 055 1861 6,679
Jackson County Walden 057 1909 1,261
Jefferson County Golden 059 1861 582,881
Kiowa County Eads 061 1889 1,489
Kit Carson County Burlington 063 1889 7,447
La Plata County Durango 067 1874 56,221
Lake County Leadville 065 1861 7,751
Larimer County Fort Collins 069 1861 356,899
Las Animas County Trinidad 071 1866 14,266
Lincoln County Hugo 073 1889 5,585
Logan County Sterling 075 1887 22,409
Mesa County Grand Junction 077 1883 154,210
Mineral County Creede 079 1893 824
Moffat County Craig 081 1911 13,283
Montezuma County Cortez 083 1889 26,031
Montrose County Montrose 085 1883 42,758
Morgan County Fort Morgan 087 1889 29,068
Otero County La Junta 089 1889 18,282
Ouray County Ouray 091 1877 4,952
Park County Fairplay 093 1861 18,845
Phillips County Holyoke 095 1889 4,290
Pitkin County Aspen 097 1881 17,767
Prowers County Lamar 099 1889 12,022
Pueblo County Pueblo 101 1861 168,424
Rio Blanco County Meeker 103 1889 6,384
Rio Grande County Del Norte 105 1874 11,305
Routt County Steamboat Springs 107 1877 25,638
Saguache County Saguache 109 1866 6,592
San Juan County Silverton 111 1876 589
San Miguel County Telluride 113 1883 8,049
Sedgwick County Julesburg 115 1889 2,322
Summit County Breckenridge 117 1861 31,011
Teller County Cripple Creek 119 1899 25,388
Washington County Akron 121 1887 4,868
Weld County Greeley 123 1861 324,492
Yuma County Wray 125 1889 10,003


10 Most Populous Colorado Counties

1. Denver County  

colorado counties

Denver is a consolidated city and a county government. It was established in 1858 as a mining town during the heady days of the Pike’s Peak Gold Rush.

Denver is the capital and the most populous city in Colorado with an estimated population of 735,538.  Denver is U.S.’s 19th most populous city and the 5th most populous state capital.

2. El Paso County 

colorado counties

El Paso County was founded on November 1, 1861. Its largest city and county seat is Colorado Springs which is the second-most populous city in Colorado.

According to the U.S. Census Bureau, El Paso County’s population as of 2019 was estimated to be 720,403, making it the second-most populous county in Colorado.

El Paso County is home to numerous military sites such as the United States Air Force Academy, Fort Carson Army, North American Aerospace Defense Command (NORAD), Schriever Air Force Base, and Peterson Air Force Base.

3. Arapahoe County

colorado counties

Arapahoe County is the third-most populous county in Colorado with an estimated population of 656,590. It was founded in 1861 and its county seat is Littleton and its largest city is Aurora.

Arapahoe County was named for the Arapaho Native American tribe, who once lived in the region.

4. Jefferson County 

colorado counties

Jefferson County was established on November 1, 1861. It is the fourth most populous county in Colorado with an estimated population of 582,881. Its county seat is Golden and its largest city is Lakewood.

Jefferson County’s slogan is the “Gateway to the Rocky Mountains” and it is commonly nicknamed JeffCo.  

5. Adams County  

Adams County was founded April 15, 1901, and named for Alva Adams an American politician. It is the fifth most populous county in Colorado with an estimated population of 517,421.

Its county seat is Brighton and its largest city is Thornton.

6. Larimer County  

colorado counties

Larimer County was founded November 1, 1861, and named for William Larimer, Jr, the founder of Denver. Its county seat and largest city is Fort Collins.  

Larimer County is the sixth most populous county in Colorado with an estimated population of 356,899.

7. Douglas County  

colorado counties

As of 2019, Douglas County’s population was estimated to be 351,154, making it the seventh most populous county in Colorado.

The largest community in Douglas County is Highlands Ranch and its county seat is Castle Rock. Douglas County was created in 1861 and was named for Stephen A. Douglas.

8. Boulder County  

colorado counties

Boulder County was founded in 1861 and named for Boulder City and Boulder Creek. Its largest city and county seat is Boulder.

As of 2019, its population was estimated to be 326,196 making it the eighth most populous county in Colorado.

9. Weld County  

Weld County estimated population as of 2019 was 324,492, making it the ninth most populous county in Colorado. It is also the 3rd largest county in Colorado by area covering 4,017 square miles.

Weld County is Colorado’s largest cattle producer, accounting for about half of the state’s total cattle inventory.

It is also one of the largest providers of grains and sugar beets making it one of the richest agricultural counties in the United States.

10. Pueblo County  

colorado counties

Pueblo County had a population of 168,424 in 2019, making it the tenth most populous county in Colorado. The county was founded in 1861 and was named for the historic City of Pueblo.

Its county seat and largest city is Pueblo.  



That was a nice one on Colorado Counties. We deserve some accolades for scouring the web and bringing to your table The 64 Colorado Counties properly arranged with the Year Formed, County Seat, Population, and Area.

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