The U.S.

State of Colorado Colorado (, other variants) is a state in the Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the western edge of the ...

is divided into 64 counties. Two of these counties, the City and County of Broomfield and the City and County of Denver, have consolidated city and county governments. Denver serves as the state capital. Counties are important units of government in Colorado since there are no

civil township A civil township is a widely used unit of local government in the United States that is subordinate to a county, most often in the northern and midwestern parts of the country. The term town is used in New England, New York, and Wisconsin to ref ...

s or other

minor civil division A minor civil division (MCD) is a term used by the United States Census Bureau for primary governmental and/or administrative divisions of a county or county-equivalent, typically a municipal government such as a city, town, or civil township. MCD ...

s. El Paso County with a 2020 population of 730,395 is the most populous Colorado county, while San Juan County with a 2020 population of 705 is the least populous.

Las Animas County Las Animas County is a county located in the U.S. state of Colorado. As of the 2020 census, the population was 14,555. The county seat is Trinidad. The county takes its name from the Mexican Spanish name of the Purgatoire River, originally ...

with an area of is the most extensive Colorado county, while the City and County of Broomfield with an area of is the least extensive. The City and County of Denver with a 2020 population density of 4,674 residents per square mile (1,805 km⁻²) is the most densely populated Colorado county, while Hinsdale County with a 2020 population density of 0.71 resident per square mile (0.27 km⁻²) is the least densely populated. Mount Elbert, the highest summit of Colorado and the entire

Rocky Mountains The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of western Canada, to New Mexico ...

at elevation, is located in Lake County. The point where the Arikaree River flows out of Yuma County and into

Kansas Kansas () is a U.S. state, state in the Midwestern United States, Midwestern United States. Its Capital city, capital is Topeka, Kansas, Topeka, and its largest city is Wichita, Kansas, Wichita. Kansas is a landlocked state bordered by Nebras ...

is the lowest point in Colorado at elevation. This point, which is the highest low point of any state, is higher than the high points of 18 states and the District of Columbia. __TOC__

History

On November 1, 1861, the new

Territory of Colorado The Territory of Colorado was an organized incorporated territory of the United States that existed from February 28, 1861, until August 1, 1876, when it was admitted to the Union as the State of Colorado. The territory was organized in the ...

created 17 original counties: Arapahoe, Boulder, Clear Creek, Costilla, Douglas, El Paso, Fremont, Gilpin, Guadalupe, Huerfano, Jefferson, Lake, Larimer, Park, Pueblo, Summit, and Weld; plus the Cheyenne Reserve. On February 9, 1866, the first new county, Las Animas, was created, followed by Saguache in December of that year. Bent County was created in February 1870, followed by Greenwood the following month. On February 2, 1874, Grand County and Elbert County were formed, and on February 10, La Plata, Hinsdale, and Rio Grande counties were created. Greenwood was absorbed into Bent on February 5. The last county to be created under the Colorado Territory name was San Juan County, created three months before statehood. By the time Colorado became a state on August 1, 1876, it had only 26 counties. In January 1877, Routt and Ouray were formed, followed by Gunnison and Custer counties in March. In February 1879, Chaffee County was created. From February 8–10, 1879, Lake county was renamed Carbonate County. In 1881, Dolores County and Pitkin County were created. In 1883, Montrose, Mesa, Garfield, Eagle, Delta, and San Miguel counties were formed, leaving the total number of counties at 39. The number rose to 40 in 1885 with the creation of Archuleta County on April 14. Washington County and Logan County were both created in 1887. Between February 19 and April 16 in 1889, Morgan, Yuma, Cheyenne, Otero, Rio Blanco, Phillips, Sedgwick, Kiowa, Kit Carson, Lincoln, Prowers, Baca, and Montezuma counties were formed, bringing the total to 55. By 1900, Mineral County and Teller County had been added. On November 15, 1902, Arapahoe County was split into Adams and South Arapahoe Counties, and Denver was consolidated as a city and county from portions of both newly formed counties on December 1, 1902. By 1912, Jackson County, Moffat County, and Crowley County had been created. Alamosa was created in 1913, and in 2001, Broomfield was consolidated as a city and county, bringing the total to 64 counties.

The 64 counties of the State of Colorado

Population estimates

United States Census Bureau The United States Census Bureau (USCB), officially the Bureau of the Census, is a principal agency of the U.S. Federal Statistical System, responsible for producing data about the American people and economy. The Census Bureau is part of th ...

population estimates for July 1, 2021 are in included in the

Population history of Colorado counties This list ranks the 64 counties of the U.S. State of Colorado by population as of , as estimated by the United States Census Bureau. This list also details the county population changes since the 2000 United States Census. El Paso ...

. With a 2021 population of 737,867, El Paso County remains the most populous county, while San Juan County with a 2021 population of 733 remains the least populous. Five of the 64 Colorado counties now have more than 500,000 residents, while 12 have fewer than 5,000 residents.

Former counties

The following sortable table lists all the historic counties of the Territory of New Mexico, the Territory of Utah, the

Territory of Kansas The Territory of Kansas was an organized incorporated territory of the United States that existed from May 30, 1854, until January 29, 1861, when the eastern portion of the territory was admitted to the Union as the free state of Kansas. ...

, and the extralegal Territory of Jefferson that previously existed within the boundaries of the present

, as well as the three defunct counties of the

and the three defunct counties of the

County high points

Of the 64 Colorado counties, 20 counties extend above elevation, 32 counties extend above , 42 counties extend above , and all 64 Colorado counties extend above .

County mean elevation

Of Colorado's 64 counties, 4 counties have a

mean There are several kinds of mean in mathematics, especially in statistics. Each mean serves to summarize a given group of data, often to better understand the overall value ( magnitude and sign) of a given data set. For a data set, the '' ar ...

elevation The elevation of a geographic location is its height above or below a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational surface (see Geodetic datum § ...

above elevation, 22 counties have a mean elevation above , 32 counties have a mean elevation above , and all 64 counties have a mean elevation above . The following 13 Colorado counties have highest mean elevation of any county in the United States, exceeding even the Denali Borough of

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U ...

County firsts

:1.

Costilla County Costilla County (Spanish for "rib") is a county located in the U.S. state of Colorado. As of the 2020 census, the population was 3,499. The county seat is San Luis, the oldest continuously occupied town in Colorado. History On July 8, 1694 ...

was the first area within the present State of Colorado to be settled by Europeans in 1851. :2. Taos County, created by the Territory of New Mexico in 1852, was the first organized county to extend into the area of the present State of Colorado. :3.

Arapahoe County Arapahoe County may refer to: *Arapahoe County, Colorado *Arapahoe County, Kansas Territory Arapahoe County was a county of Kansas Territory in the United States that existed from August 25, 1855, until Kansas's admission into the Union on January ...

, created by the

in 1855, was the first county created exclusively within the area of the present State of Colorado. :4. On November 28, 1859, the extralegal Territory of Jefferson created 12 counties: :5. On November 1, 1861, the

created the 17 original Colorado counties: :6. Of the 17 original Colorado counties created in 1861, only Gilpin County and

Clear Creek County Clear Creek County is a county located in the U.S. state of Colorado. As of the 2020 census, the population was 9,397. The county seat is Georgetown. Clear Creek County is part of the Denver metropolitan area. History Clear Creek County ...

have retained their original boundaries with only minor survey changes. :7. Guadaloupe County was the first Colorado county to be renamed after only six days in 1861. :8.

was the first new Colorado county to be created (in 1866) after the original 17 counties. :9. Greenwood County was the longest lived former Colorado county, existing four years from 1870 to 1874. :10. In 1876, San Juan County became the last county created by the

, bringing the total number of territorial counties to 26. :11. In 1877, Ouray County became the first county created by the new

. :12. Carbonate County was the shortest lived former Colorado county, existing only two days in 1879 before being dissolved. :13. The City and County of Broomfield became the newest Colorado county in 2001, bring the total number of counties to 64.

County distinctions

:1. El Paso County (91) and the City and County of Denver (94) and are among the 100 most populous counties of the United States. :2. San Juan County (16), Hinsdale County (25), Mineral County (32), Jackson County (55), Kiowa County (59), and Cheyenne County (80) are among the 100 least populous counties of the United States. :3. Jefferson County borders ten adjacent counties, the most of any Colorado county. :4. Delta County and the City and County of Denver each border only three adjacent counties, the fewest of Colorado counties. :5.

Weld County Weld County is a county located in the U.S. state of Colorado. As of the 2020 census, the population was 328,981. The county seat is Greeley. Weld County comprises the Greeley, CO Metropolitan Statistical Area, which is included in the Denv ...

has the most incorporated municipalities of any Colorado county with 31. :6. The following nine Colorado counties have no incorporated municipalities other than their county seat: :7. Of all 64 Colorado counties, only Conejos County has a county seat that is not an incorporated municipality. :8. The City and County of Denver and the City and County of Broomfield are the only two Colorado counties with

enclave An enclave is a territory (or a small territory apart of a larger one) that is entirely surrounded by the territory of one other state or entity. Enclaves may also exist within territorial waters. ''Enclave'' is sometimes used improperly to deno ...

Boulder County Boulder County is a county located in the U.S. state of Colorado of the United States. As of the 2020 census, the population was 330,758. The most populous municipality in the county and the county seat is Boulder. Boulder County comprises t ...

, and Jefferson County are the only three Colorado counties with

exclave An enclave is a territory (or a small territory apart of a larger one) that is entirely surrounded by the territory of one other state or entity. Enclaves may also exist within territorial waters. ''Enclave'' is sometimes used improperly to deno ...

Gallery

USAFA air gardens.jpg, 1. The

United States Air Force Academy The United States Air Force Academy (USAFA) is a United States service academy in El Paso County, Colorado, immediately north of Colorado Springs. It educates cadets for service in the officer corps of the United States Air Force and U ...

El Paso County, Colorado El Paso County is a county located in the U.S. state of Colorado. The 2020 Census recorded its population as 730,395. The Census Bureau's 2020 result indicates it is the most populous county in Colorado, surpassing the City and County of D ...

, alt=Photo of the United States Air Force Academy in El Paso County, Colorado Denver Capitol.jpg, 2. The

Colorado State Capitol The Colorado State Capitol Building, located at 200 East Colfax Avenue in Denver, Colorado, United States, is the home of the Colorado General Assembly and the offices of the Governor of Colorado and Lieutenant Governor of Colorado. Histor ...

in the City and County of Denver, alt=Photo of the Colorado State Capitol in the City and County of Denver Key Savings and Loan Association Building.JPG, 3. A bank building in Arapahoe County, Colorado, alt=Photo of a bank building in Arapahoe County, Colorado Colorado School of Mines (5893276634).jpg, 4. The Colorado School of Mines in

Jefferson County, Colorado Jefferson County is a county located in the U.S. state of Colorado. As of the 2020 census, the population was 582,910, making it the fourth-most populous county in Colorado. The county seat is Golden, and the most populous city is Lakewood. ...

, alt=Photo of the Colorado School of Mines in Jefferson County, Colorado The Childrens Hospital of Denver Front.JPG, 5. The Anschutz Medical Campus in Adams County, Colorado, alt=Photo of the Anschutz Medical Campus in Adams County, Colorado Fountain Valley Trail (5974714678).jpg, 6. Roxborough State Park in Douglas County, Colorado, alt=Photo of Roxborough State Park in Douglas County, Colorado CSU University Center for the Arts.jpg, 7.

Colorado State University Colorado State University (Colorado State or CSU) is a Public university, public Land-grant university, land-grant research university in Fort Collins, Colorado. It is the flagship university of the Colorado State University System. Colorado S ...

Larimer County, Colorado Larimer County is a county located in the U.S. state of Colorado. As of the 2020 census, the population was 359,066. The county seat and most populous city is Fort Collins. The county was named for William Larimer, Jr., the founder of Denver ...

, alt=Photo of Colorado State University in Larimer County, Colorado Stampede Parade.jpg, 8. The Greeley Stampede Parade in

Weld County, Colorado Weld County is a county located in the U.S. state of Colorado. As of the 2020 census, the population was 328,981. The county seat is Greeley. Weld County comprises the Greeley, CO Metropolitan Statistical Area, which is included in the Denve ...

, alt=Photo of the Greeley Stampede Parade‎ in Weld County, Colorado National Center for Atmospheric Research - Boulder, Colorado.jpg, 9. The National Center for Atmospheric Research in Boulder County, Colorado, alt=Photo of the National Center for Atmospheric Research in Boulder County, Colorado Historic Arkansas Riverwalk of Pueblo.JPG, 10. The

Historic Arkansas Riverwalk The Historic Arkansas Riverwalk is a riverwalk in the US city of Pueblo, Colorado, along the Arkansas River. The riverwalk was constructed as part of an effort to attract tourists and trade to the city. Its construction was inspired by the San An ...

Pueblo County, Colorado Pueblo County ( or ) is a county located in the U.S. state of Colorado. As of the 2020 census, the population was 168,162. The county seat is Pueblo. The county was named for the historic city of Pueblo which took its name from the Spanis ...

, alt=Photo of the Historic Arkansas Riverwalk in Pueblo County, Colorado

Notes

References

External links

United States Department of Commerce

United States Census BureauState of Colorado

Department of Local AffairsColorado County Clerks AssociationHistory Colorado
{{DEFAULTSORT:Counties in Colorado, List of Colorado history-related lists Lists of populated places in Colorado Local government in Colorado Colorado, List of counties in