The
U.S.
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...
State of Colorado is divided into 64
counties
A county is a geographic region of a country used for administrative or other purposesChambers Dictionary, L. Brookes (ed.), 2005, Chambers Harrap Publishers Ltd, Edinburgh in certain modern nations. The term is derived from the Old French ...
. 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
Below is an index of pages containing lists of capital cities.
National capitals
*List of national capitals
* List of national capitals by latitude
*List of national capitals by population
* List of national capitals by area
* List of capital c ...
. 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 divisions.
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 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
Mount Elbert is the highest summit of the Rocky Mountains, the highest point in the U.S. state of Colorado, and the second-highest summit in the contiguous United States (after Mount Whitney). The ultra-prominent fourteener is the highest pea ...
, 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 in ...
at elevation, is located in
Lake County. The point where the
Arikaree River
The Arikaree River is a river in the central Great Plains of North America. It lies mostly in the American state of Colorado, draining land between the North and South Forks of the Republican River, and it flows into the North Fork in Nebraska ...
flows out of
Yuma County and into
Kansas
Kansas () is a state in the Midwestern United States. Its capital is Topeka, and its largest city is Wichita. Kansas is a landlocked state bordered by Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to the ...
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 the ...
population estimates for July 1, 2021 are in included in the
Population history of Colorado counties.
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
A county is a geographic region of a country used for administrative or other purposesChambers Dictionary, L. Brookes (ed.), 2005, Chambers Harrap Publishers Ltd, Edinburgh in certain modern nations. The term is derived from the Old French ...
of the
Territory of New Mexico
The Territory of New Mexico was an organized incorporated territory of the United States from September 9, 1850, until January 6, 1912. It was created from the U.S. provisional government of New Mexico, as a result of '' Nuevo México'' becoming ...
, the
Territory of Utah
The Territory of Utah was an organized incorporated territory of the United States that existed from September 9, 1850, until January 4, 1896, when the final extent of the territory was admitted to the Union as the State of Utah, the 45th state ...
, 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
The Territory of Jefferson was an extralegal and unrecognized United States territory that existed from October 24, 1859 until the creation of the Colorado Territory on February 28, 1861. The Jefferson Territory, named for Founding Father and Un ...
that previously existed within the boundaries of the present
State of Colorado, as well as the three defunct counties of the
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 ...
and the three defunct counties of the
State of Colorado.
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 ''arithme ...
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 § Vert ...
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
The Denali Borough is a Borough (United States), borough located in the U.S. state of Alaska. As of the 2020 United States Census, 2020 census the population of the borough was 1,619, down from 1,826 in 2010.
The borough seat and most populat ...
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.S., ...
.
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
Taos County is a county in the U.S. state of New Mexico. As of the 2010 census, the population was 32,937. Its county seat is Taos. The county was formed in 1852 as one of the original nine counties in New Mexico Territory.
Taos County compris ...
, created by the
Territory of New Mexico
The Territory of New Mexico was an organized incorporated territory of the United States from September 9, 1850, until January 6, 1912. It was created from the U.S. provisional government of New Mexico, as a result of '' Nuevo México'' becoming ...
in 1852, was the first organized county to extend into the area of the present State of Colorado.
:3.
Arapahoe County, created by 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.
...
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
The Territory of Jefferson was an extralegal and unrecognized United States territory that existed from October 24, 1859 until the creation of the Colorado Territory on February 28, 1861. The Jefferson Territory, named for Founding Father and Un ...
created 12 counties:
[
:5. On November 1, 1861, the ]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 the 17 original Colorado counties:
:6. Of the 17 original Colorado counties created in 1861, only Gilpin County
Gilpin County is a county located in the U.S. state of Colorado, smallest in land area behind only the City and County of Broomfield. As of the 2020 census, the population was 5,808. The county seat is Central City. The county was formed in 18 ...
and 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. Las Animas County was the first new Colorado county to be created (in 1866) after the original 17 counties.
:9. Greenwood County Greenwood County is the name of two counties in the United States:
* Greenwood County, Kansas
Greenwood County (county code GW) is a county located in the southeast portion of the U.S. state of Kansas. As of the 2020 census, the county populat ...
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 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 ...
, bringing the total number of territorial counties to 26.
:11. In 1877, Ouray County
Ouray County is a county located in the U.S. state of Colorado. As of the 2020 census, the population was 4,874. The county seat is Ouray. Because of its rugged mountain topography, Ouray County is also known as the Switzerland of America.
H ...
became the first county created by the new State of Colorado.
: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 Denver ...
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
Conejos County is a county located in the U.S. state of Colorado. As of the 2020 census, the population was 7,461. The county seat is the unincorporated community of Conejos.
Being 50.7% Hispanic in 2020, Conejos was Colorado's largest Hispa ...
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 ...
s. Arapahoe County, Boulder County, 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 ...
s.
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 Uni ...
in 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 De ...
, 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.
History ...
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
Arapahoe County ( ) is a county located in the U.S. state of Colorado. As of the 2020 United States Census, 2020 census, its population was 655,070, making it the third-most populous county in Colorado. The county seat is Littleton, Colorado, Li ...
, alt=Photo of a bank building in Arapahoe County, Colorado
Colorado School of Mines (5893276634).jpg, 4. The Colorado School of Mines
The Colorado School of Mines, informally called Mines, is a public research university in Golden, Colorado, founded in 1874. The school offers both undergraduate and graduate degrees in engineering, science, and mathematics, with a focus on ener ...
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
The University of Colorado Anschutz Medical Campus is the academic health sciences campus in Aurora, Colorado that houses the University of Colorado's six health sciences-related schools and colleges, including the University of Colorado School ...
in Adams County, Colorado
Adams County is a county located in the U.S. state of Colorado. As of the 2020 United States Census, 2020 census, the population was 519,572. The county seat is Brighton, Colorado, Brighton. The county is named for Alva Adams (governor), Alva Ad ...
, alt=Photo of the Anschutz Medical Campus in Adams County, Colorado
Fountain Valley Trail (5974714678).jpg, 6. Roxborough State Park
Roxborough State Park is a state park of Colorado, United States, known for dramatic red sandstone formations. Located in Douglas County south of Denver, Colorado, the park was established in 1975. In 1980 it was recognized as a National Na ...
in Douglas County, Colorado
Douglas County is a county located in the U.S. state of Colorado. As of the 2020 census, the population was 357,978. The county seat is Castle Rock.
Douglas County is part of the Denver-Aurora-Lakewood, Colorado, metropolitan statistica ...
, 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 land-grant research university in Fort Collins, Colorado. It is the flagship university of the Colorado State University System. Colorado State University is classified among "R1: ...
in 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 Denver ...
, 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
The US National Center for Atmospheric Research (NCAR ) is a US federally funded research and development center (FFRDC) managed by the nonprofit University Corporation for Atmospheric Research (UCAR) and funded by the National Science Foundatio ...
in Boulder County, Colorado
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 ...
, 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 ...
in 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 Spanish lan ...
, alt=Photo of the Historic Arkansas Riverwalk in Pueblo County, Colorado
See also
*List of populated places in Colorado
A ''list'' is any set of items in a row. List or lists may also refer to:
People
* List (surname)
Organizations
* List College, an undergraduate division of the Jewish Theological Seminary of America
* SC Germania List, German rugby unio ...
**List of census-designated places in Colorado
The U.S. has 210 census-designated places. The United States Census Bureau defines certain unincorporated communities as census-designated places (CDPs) for enumeration in each decennial census. The Census Bureau defined 187 CDPs in Colorado ...
*** Population history of Colorado census-designated places
**List of counties in Colorado
***List of county seats in Colorado
This is a list of County seat#United States, county seats in the United States, U.S. Colorado, State of Colorado and its predecessors: the Colorado Territory, Territory of Colorado and the extralegal Jefferson Territory, Territory of Jefferson.
...
*** Population history of Colorado counties
**List of forts in Colorado
This is a list of military and trading forts established in the U.S. State of Colorado.
History
The initial forts, built in the first half of the 19th century, were early communities of commerce between Native Americans, trappers, and trader ...
**List of ghost towns in Colorado
This is a list of some ghost towns in the U.S. State of Colorado. Colorado has over 1,500 ghost towns, although visible remains of only about 640 still exist. Due to incomplete records and legends that are now accepted as fact, no exhaustive l ...
**List of historic places in Colorado
There are more than 1,500 properties and historic districts in Colorado listed on the National Register of Historic Places. They are distributed over 63 of Colorado's 64 counties; only the City and County of Broomfield has none.
__NOTOC__
C ...
**List of municipalities in Colorado
The U.S. State of Colorado has 272 active incorporated municipalities, comprising 197 towns, 73 cities, and two consolidated city and county governments. At the 2020 United States Census, 4,299,942 of the 5,773,714 Colorado residents (74.47%) ...
***Population history of Colorado municipalities
This is a population history of the 272 active incorporated municipalities of the US State of Colorado since the 2000 United States census as estimated by the United States Census Bureau.
With a 2021 population estimate of 711,463 residents, ...
**List of populated places in Colorado by county
A ''list'' is any set of items in a row. List or lists may also refer to:
People
* List (surname)
Organizations
* List College, an undergraduate division of the Jewish Theological Seminary of America
* SC Germania List, German rugby union ...
**
**List of statistical areas in Colorado
The U.S. state of Colorado has twenty-one statistical areas that have been delineated by the Office of Management and Budget (OMB). Statistical areas are important geographic delineations of population clusters used by the OMB, the United States ...
Notes
References
External links
United States Department of Commerce
United States Census Bureau
State of Colorado
Department of Local Affairs
Colorado County Clerks Association
History 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