List of counties in Colorado facts for kids

Kids Encyclopedia Facts
See also: List of United States counties and county-equivalents
Counties of Colorado
Location State of Colorado
Number 64
Populations 699 (San Juan) – 622,263 (El Paso)
Areas 34 square miles (88 km2) (Broomfield City and County) – 4,773.27 square miles (12,362.7 km2) (Las Animas)
Government County government
Subdivisions cities, towns, unincorporated communities, census designated place

The U.S. state of Colorado is divided into 64 counties. Counties are important units of government in Colorado since the state has no secondary civil subdivisions, such as townships. Two of these counties, the City and County of Denver and the City and County of Broomfield, have consolidated city and county governments.

Colorado's ISO 3166-2:US state code is CO and its ANSI INCITS 38:2009 state code is 08.

When the Colorado Territory first began creating counties in 1861, 17 counties (Summit, Larimer, Weld, Boulder, Gilpin, Clear Creek, Jefferson, Arapahoe, Douglas, Lake, Conejos, Costilla, Park, Fremont, El Paso, Pueblo, and Huerfano) and a Cheyenne Reserve were formed. In February 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, which was 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 split into Adams in the north and Denver was recognized as a consolidated city-county. By 1912, Jackson County, Moffat County, and Crowley County had been created. Alamosa was created in 1913, and in 2001, Broomfield was recognized as a city-county, bringing a total of 64 counties.

Table 1

County
FIPS Code

County seat

Established

Formed from

Etymology
Population
Area
Map
Adams County 001 Brighton 1902-11-15 Split from Arapahoe County. Named in honor of Alva Adams, the 5th, 10th, and 14th Governor of the State of Colorado. &&&&&&&&&0441603.&&&&&0441,603 &&&&&&&&&&&01182.2900001,182.29 sq mi
(&&&&&&&&&&&03062.&&&&&03,062 km²)
State map highlighting Adams County


Alamosa County 003 Alamosa 1913-03-08 Split from Costilla County and Conejos County. Named for the cottonwood trees which grow along the Rio Grande and its tributaries. Alamosa is a Spanish word for a cottonwood grove. &&&&&&&&&&015445.&&&&&015,445 &&&&&&&&&&&&0723.210000723.21 sq mi
(&&&&&&&&&&&01873.&&&&&01,873 km²)
State map highlighting Alamosa County


Arapahoe County 005 Littleton 1861-11-01 Created as one of the 17 original counties of the Territory of Colorado. Renamed South Arapahoe County for the five months from November 15, 1902 to April 11, 1903. Named for predecessor Arapahoe County, Kansas Territory, which in turn was named for the Arapaho Nation of Native Americans. &&&&&&&&&0572003.&&&&&0572,003 &&&&&&&&&&&&0804.410000804.41 sq mi
(&&&&&&&&&&&02083.&&&&&02,083 km²)
State map highlighting Arapahoe County


Archuleta County 007 Pagosa Springs 1885-04-14 Split from Conejos County. Named in honor of Colorado State Senator Antonio D. Archuleta. &&&&&&&&&&012084.&&&&&012,084 &&&&&&&&&&&01354.5300001,354.53 sq mi
(&&&&&&&&&&&03508.&&&&&03,508 km²)


Baca County 009 Springfield 1889-04-16 Split from Las Animas County. Named in honor of pioneer and Colorado territorial legislator Felipe Baca. &&&&&&&&&&&03788.&&&&&03,788 &&&&&&&&&&&02558.4800002,558.48 sq mi
(&&&&&&&&&&&06626.&&&&&06,626 km²)


Bent County 011 Las Animas 1870-02-11 Split from Huerfano County and former Cheyenne and Arapaho tribal land. Named in honor of frontier trader William Bent. &&&&&&&&&&&06499.&&&&&06,499 &&&&&&&&&&&01541.&700001,541.07 sq mi
(&&&&&&&&&&&03991.&&&&&03,991 km²)


Boulder County 013 Boulder 1861-11-01 Created as one of the 17 original counties of the Territory of Colorado. Named for the abundance of granite boulders along Boulder Creek. &&&&&&&&&0294567.&&&&&0294,567 &&&&&&&&&&&&0740.480000740.48 sq mi
(&&&&&&&&&&&01918.&&&&&01,918 km²)
State map highlighting Boulder County


City and County of Broomfield 014 Broomfield 2001-11-15 Split from Boulder, Adams, Jefferson, and Weld counties and reorganized as a consolidated city and county. Named for the broom corn that was formerly grown in the area. &&&&&&&&&&055889.&&&&&055,889 &&&&&&&&&&&&&033.57000033.57 sq mi
(&&&&&&&&&&&&&087.&&&&&087 km²)
State map highlighting City and County of Broomfield


Chaffee County 015 Salida 1879-02-10 Split from Carbonate County. Named in honor of Jerome Bunty Chaffee, one of Colorado's first two U.S. Senators from 1876 to 1879. &&&&&&&&&&017809.&&&&&017,809 &&&&&&&&&&&01014.1200001,014.12 sq mi
(&&&&&&&&&&&02627.&&&&&02,627 km²)
State map highlighting Chaffee County


Cheyenne County 017 Cheyenne Wells 1889-03-25 Split from Elbert and Bent counties. Named for the Cheyenne Nation of Native Americans. &&&&&&&&&&&01836.&&&&&01,836 &&&&&&&&&&&01781.9000001,781.90 sq mi
(&&&&&&&&&&&04615.&&&&&04,615 km²)


Clear Creek County 019 Georgetown 1861-11-01 Created as one of the 17 original counties of the Territory of Colorado. Named for Clear Creek which originates in the county. &&&&&&&&&&&09088.&&&&&09,088 &&&&&&&&&&&&0396.530000396.53 sq mi
(&&&&&&&&&&&01027.&&&&&01,027 km²)
State map highlighting Clear Creek County


Conejos County 021 Conejos 1861-11-01 Guadalupe County, one of the 17 original counties of the Territory of Colorado, was renamed Conejos County after six days on November 7, 1861. Named for the cottontail rabbits in the area. Conejos is a Spanish word for rabbits. &&&&&&&&&&&08256.&&&&&08,256 &&&&&&&&&&&01290.2200001,290.22 sq mi
(&&&&&&&&&&&03342.&&&&&03,342 km²)
State map highlighting Conejos County


Costilla County 023 San Luis 1861-11-01 Created as one of the 17 original counties of the Territory of Colorado. Named for the Costilla River. Costilla is a Spanish word meaning either little rib or furring timber. &&&&&&&&&&&03524.&&&&&03,524 &&&&&&&&&&&01229.3800001,229.38 sq mi
(&&&&&&&&&&&03184.&&&&&03,184 km²)
State map highlighting Costilla County


Crowley County 025 Ordway 1911-05-29 Split from Otero County. Named in honor of Colorado State Senator John H. Crowley. &&&&&&&&&&&05823.&&&&&05,823 &&&&&&&&&&&&0800.270000800.27 sq mi
(&&&&&&&&&&&02073.&&&&&02,073 km²)


Custer County 027 Westcliffe 1877-03-09 Split from Fremont County. Named in memory of George Armstrong Custer, (1839 - 1876), the U.S. Army colonel defeated and killed at the Battle of the Little Bighorn. &&&&&&&&&&&04255.&&&&&04,255 &&&&&&&&&&&&0739.240000739.24 sq mi
(&&&&&&&&&&&01915.&&&&&01,915 km²)


Delta County 029 Delta 1883-02-11 Split from Gunnison County. Named for the town of Delta located at the delta of the Uncompahgre River. &&&&&&&&&&030952.&&&&&030,952 &&&&&&&&&&&01149.4400001,149.44 sq mi
(&&&&&&&&&&&02977.&&&&&02,977 km²)
State map highlighting Delta County


City and County of Denver 031 Denver 1902-11-15 The original Arapahoe County Seat was split from Arapahoe County and reorganized as a consolidated city and county. Named to curry favor with James W. Denver, Governor of the Territory of Kansas from 1857 to 1859. &&&&&&&&&0600158.&&&&&0600,158 &&&&&&&&&&&&0155.660000155.66 sq mi
(&&&&&&&&&&&&0403.&&&&&0403 km²)
State map highlighting City and County of Denver


Dolores County 033 Dove Creek 1881-03-04 Split from Ouray County. Named for the Dolores River, which was originally named el Rio de Nuestra Senora de los Dolores, which is Spanish for the River of our Lady of Sorrows. &&&&&&&&&&&02064.&&&&&02,064 &&&&&&&&&&&01076.9300001,076.93 sq mi
(&&&&&&&&&&&02789.&&&&&02,789 km²)


Douglas County 035 Castle Rock 1861-11-01 Created as one of the 17 original counties of the Territory of Colorado. Named in honor of Stephen Arnold Douglas, (1813 - 1861), U.S. Senator from Illinois from 1847 to 1861. &&&&&&&&&0285465.&&&&&0285,465 &&&&&&&&&&&&0842.300000842.30 sq mi
(&&&&&&&&&&&02182.&&&&&02,182 km²)
State map highlighting Douglas County


Eagle County 037 Eagle 1883-02-11 Split from Summit County. Named for the Eagle River which originates in the county. &&&&&&&&&&052197.&&&&&052,197 &&&&&&&&&&&01700.7600001,700.76 sq mi
(&&&&&&&&&&&04405.&&&&&04,405 km²)
State map highlighting Eagle County


El Paso County 041 Colorado Springs 1861-11-01 Created as one of the 17 original counties of the Territory of Colorado. Named for Ute Pass, which connects the Great Plains to South Park and was formerly located within the county. El Paso means the pass in Spanish. &&&&&&&&&0622263.&&&&&0622,263 &&&&&&&&&&&02128.6000002,128.60 sq mi
(&&&&&&&&&&&05513.&&&&&05,513 km²)
State map highlighting El Paso County


Elbert County 039 Kiowa 1874-02-02 Split from Douglas County. Named in honor of Samuel Hitt Elbert, the sixth Governor of the Territory of Colorado. &&&&&&&&&&023086.&&&&&023,086 &&&&&&&&&&&01849.&800001,849.08 sq mi
(&&&&&&&&&&&04789.&&&&&04,789 km²)


Fremont County 043 Cañon City 1861-11-01 Created as one of the 17 original counties of the Territory of Colorado. Named in honor of John Charles Frémont (1813 - 1890), the explorer, U.S. Army general, and U.S. Senator from California. &&&&&&&&&&046824.&&&&&046,824 &&&&&&&&&&&01533.&900001,533.09 sq mi
(&&&&&&&&&&&03971.&&&&&03,971 km²)
State map highlighting Fremont County


Garfield County 045 Glenwood Springs 1883-02-10 Split from Summit County. Named in honor of James Abram Garfield (1831 - 1881), the twentieth President of the United States. &&&&&&&&&&056389.&&&&&056,389 &&&&&&&&&&&02958.2300002,958.23 sq mi
(&&&&&&&&&&&07662.&&&&&07,662 km²)
State map highlighting Garfield County


Gilpin County 047 Central City 1861-11-01 Created as one of the 17 original counties of the Territory of Colorado. Named in honor of William Gilpin, the first Governor of the Territory of Colorado. &&&&&&&&&&&05441.&&&&&05,441 &&&&&&&&&&&&0150.150000150.15 sq mi
(&&&&&&&&&&&&0389.&&&&&0389 km²)


Grand County 049 Hot Sulphur Springs 1874-02-02 Split from Summit County. Named for the Grand River which originates in the county. The Grand River was renamed the Colorado River in 1921, but the county retains the original name. &&&&&&&&&&014843.&&&&&014,843 &&&&&&&&&&&01868.5300001,868.53 sq mi
(&&&&&&&&&&&04839.&&&&&04,839 km²)
State map highlighting Grand County


Gunnison County 051 Gunnison 1877-03-09 Split from Lake County. Named in honor of John Williams Gunnison, the U.S. Army captain who explored the region. &&&&&&&&&&015324.&&&&&015,324 &&&&&&&&&&&03259.2200003,259.22 sq mi
(&&&&&&&&&&&08441.&&&&&08,441 km²)
State map highlighting Gunnison County


Hinsdale County 053 Lake City 1874-02-10 Split from Lake, Conejos, and Costilla counties. Named in honor of George Aaron Hinsdale, a Lieutenant Governor of the Territory of Colorado. &&&&&&&&&&&&0843.&&&&&0843 &&&&&&&&&&&01123.3500001,123.35 sq mi
(&&&&&&&&&&&02909.&&&&&02,909 km²)
State map highlighting Hinsdale County


Huerfano County 055 Walsenburg 1861-11-01 Created as one of the 17 original counties of the Territory of Colorado. Named for Huerfano Butte, a solitary volcanic plug. Huerfano is a Spanish word meaning orphan. &&&&&&&&&&&06711.&&&&&06,711 &&&&&&&&&&&01592.3700001,592.37 sq mi
(&&&&&&&&&&&04124.&&&&&04,124 km²)


Jackson County 057 Walden 1909-05-05 Split from Larimer County. Named in honor of Andrew Jackson (1767 - 1845), the seventh President of the United States. &&&&&&&&&&&01394.&&&&&01,394 &&&&&&&&&&&01619.7500001,619.75 sq mi
(&&&&&&&&&&&04195.&&&&&04,195 km²)
Jefferson County 059 Golden 1861-11-01 Created as one of the 17 original counties of the Territory of Colorado. Named for its extralegal predecessor county, Jefferson County, Jefferson Territory, which in turn was named in honor of Thomas Jefferson (1743 - 1826), the author of the Declaration of Independence and the third President of the United States. &&&&&&&&&0534543.&&&&&0534,543 &&&&&&&&&&&&0772.850000772.85 sq mi
(&&&&&&&&&&&02002.&&&&&02,002 km²)
State map highlighting Jefferson County


Kiowa County 061 Eads 1889-04-11 Split from Bent County. Named for the Kiowa Nation of Native Americans. &&&&&&&&&&&01398.&&&&&01,398 &&&&&&&&&&&01785.9000001,785.90 sq mi
(&&&&&&&&&&&04625.&&&&&04,625 km²)


Kit Carson County 063 Burlington 1889-04-11 Split from Elbert County. Named in honor of Christopher Houston "Kit" Carson, the famous frontier scout and soldier. &&&&&&&&&&&08270.&&&&&08,270 &&&&&&&&&&&02162.4300002,162.43 sq mi
(&&&&&&&&&&&05601.&&&&&05,601 km²)


La Plata County 067 Durango 1874-02-10 Split from Lake and Conejos counties. Named for the many silver deposits in the area. La plata is a Spanish expression for the silver. &&&&&&&&&&051334.&&&&&051,334 &&&&&&&&&&&01700.4400001,700.44 sq mi
(&&&&&&&&&&&04404.&&&&&04,404 km²)
State map highlighting La Plata County


Lake County 065 Leadville 1861-11-01 Created as one of the 17 original counties of the Territory of Colorado. Renamed Carbonate County for the two days from February 8–10, 1879. Named for the Twin Lakes in the county. &&&&&&&&&&&07310.&&&&&07,310 &&&&&&&&&&&&0383.550000383.55 sq mi
(&&&&&&&&&&&&0993.&&&&&0993 km²)
State map highlighting Lake County


Larimer County 069 Fort Collins 1861-11-01 Created as one of the 17 original counties of the Territory of Colorado. Named in honor of William Larimer, a pioneer entrepreneur. &&&&&&&&&0299630.&&&&&0299,630 &&&&&&&&&&&02631.7500002,631.75 sq mi
(&&&&&&&&&&&06816.&&&&&06,816 km²)
State map highlighting Larimer County


Las Animas County 071 Trinidad 1866-02-09 Split from Huerfano County. Named for the Purgatoire River, which was originally named el Rio de las Animas Perdidas, which is Spanish for the River of the Souls in Purgatory. &&&&&&&&&&015507.&&&&&015,507 &&&&&&&&&&&04773.2700004,773.27 sq mi
(&&&&&&&&&&012363.&&&&&012,363 km²)
State map highlighting Las Animas County


Lincoln County 073 Hugo 1889-04-11 Split from Elbert and Bent counties. Named in honor of Abraham Lincoln (1809 - 1865), the sixteenth President of the United States. &&&&&&&&&&&05467.&&&&&05,467 &&&&&&&&&&&02585.2100002,585.21 sq mi
(&&&&&&&&&&&06696.&&&&&06,696 km²)


Logan County 075 Sterling 1887-02-25 Split from Weld County. Named in honor of John Alexander Logan (1826 - 1886), a U.S. Army general and U.S. Senator from Illinois. &&&&&&&&&&022709.&&&&&022,709 &&&&&&&&&&&01845.3100001,845.31 sq mi
(&&&&&&&&&&&04779.&&&&&04,779 km²)
State map highlighting Logan County


Mesa County 077 Grand Junction 1883-02-14 Split from Gunnison County. Named for the mesa formations which are widespread through the area. &&&&&&&&&0146723.&&&&&0146,723 &&&&&&&&&&&03345.6900003,345.69 sq mi
(&&&&&&&&&&&08665.&&&&&08,665 km²)
State map highlighting Mesa County


Mineral County 079 Creede 1893-03-27 Split from Hinsdale, Rio Grande, and Saguache counties. Named from the plentiful mineral deposits found in the area. &&&&&&&&&&&&0712.&&&&&0712 &&&&&&&&&&&&0878.160000878.16 sq mi
(&&&&&&&&&&&02274.&&&&&02,274 km²)


Moffat County 081 Craig 1911-02-27 Split from Routt County. Named in honor of railroad pioneer David H. Moffat. &&&&&&&&&&013795.&&&&&013,795 &&&&&&&&&&&04755.8600004,755.86 sq mi
(&&&&&&&&&&012318.&&&&&012,318 km²)
State map highlighting Moffat County


Montezuma County 083 Cortez 1889-04-16 Split from La Plata County. Named in honor of Aztec leader Moctezuma II. Ruins in the area were once thought to be Aztec. &&&&&&&&&&025535.&&&&&025,535 &&&&&&&&&&&02035.8000002,035.80 sq mi
(&&&&&&&&&&&05273.&&&&&05,273 km²)
State map highlighting Montezuma County


Montrose County 085 Montrose 1883-02-11 Split from Gunnison County. Named for the town of Montrose, which in turn was probably named from the novel A Legend of Montrose, published in 1819 by Walter Scott. &&&&&&&&&&041276.&&&&&041,276 &&&&&&&&&&&02246.4300002,246.43 sq mi
(&&&&&&&&&&&05818.&&&&&05,818 km²)
State map highlighting Montrose County


Morgan County 087 Fort Morgan 1889-02-19 Split from Weld County. Named for old Fort Morgan, which in turn was named in honor of U.S. Army Colonel Christopher A. Morgan. &&&&&&&&&&028159.&&&&&028,159 &&&&&&&&&&&01293.8300001,293.83 sq mi
(&&&&&&&&&&&03351.&&&&&03,351 km²)
State map highlighting Morgan County


Otero County 089 La Junta 1889-03-25 Split from Bent County. Named in honor of Miguel A. Otero of the prominent Otero family of the Southwest. &&&&&&&&&&018831.&&&&&018,831 &&&&&&&&&&&01267.6600001,267.66 sq mi
(&&&&&&&&&&&03283.&&&&&03,283 km²)
State map highlighting Otero County


Ouray County 091 Ouray 1877-01-18 Split from Hinsdale and Lake counties. Renamed Uncompaghre County for four days from 1883-02-27, to 1883-03-02. Named in honor of Ouray, a Ute Native American leader. &&&&&&&&&&&04436.&&&&&04,436 &&&&&&&&&&&&0542.300000542.30 sq mi
(&&&&&&&&&&&01405.&&&&&01,405 km²)


Park County 093 Fairplay 1861-11-01 Created as one of the 17 original counties of the Territory of Colorado. Named for South Park which occupies most of the county. &&&&&&&&&&016206.&&&&&016,206 &&&&&&&&&&&02209.3600002,209.36 sq mi
(&&&&&&&&&&&05722.&&&&&05,722 km²)


Phillips County 095 Holyoke 1889-03-27 Split from Logan County. Named in honor of R.O. Phillips, secretary of the Lincoln Land Company, which sold farmsteads in the area. &&&&&&&&&&&04442.&&&&&04,442 &&&&&&&&&&&&0688.300000688.30 sq mi
(&&&&&&&&&&&01783.&&&&&01,783 km²)


Pitkin County 097 Aspen 1881-02-23 Split from Gunnison County. Named in honor of Frederick Walker Pitkin, the second Governor of the State of Colorado. &&&&&&&&&&017148.&&&&&017,148 &&&&&&&&&&&&0970.370000970.37 sq mi
(&&&&&&&&&&&02513.&&&&&02,513 km²)
State map highlighting Pitkin County


Prowers County 099 Lamar 1889-04-11 Split from Bent County. Named in honor of John W. Prowers, a pioneer of the Arkansas River valley. &&&&&&&&&&012551.&&&&&012,551 &&&&&&&&&&&01645.3700001,645.37 sq mi
(&&&&&&&&&&&04261.&&&&&04,261 km²)
State map highlighting Prowers County


Pueblo County 101 Pueblo 1861-11-01 Created as one of the 17 original counties of the Territory of Colorado. Named for historic town of Pueblo. Pueblo is a Spanish word meaning village or people. &&&&&&&&&0159063.&&&&&0159,063 &&&&&&&&&&&02396.7700002,396.77 sq mi
(&&&&&&&&&&&06208.&&&&&06,208 km²)
State map highlighting Pueblo County


Rio Blanco County 103 Meeker 1889-03-25 Split from Garfield County. Named for the White River, which was originally named Rio Blanco in Spanish. &&&&&&&&&&&06666.&&&&&06,666 &&&&&&&&&&&03226.2400003,226.24 sq mi
(&&&&&&&&&&&08356.&&&&&08,356 km²)
State map highlighting Rio Blanco County


Rio Grande County 105 Del Norte 1874-02-10 Split from Costilla County and Conejos County counties. Named for the Rio Grande, which flows through the area. &&&&&&&&&&011982.&&&&&011,982 &&&&&&&&&&&&0913.100000913.10 sq mi
(&&&&&&&&&&&02365.&&&&&02,365 km²)
State map highlighting Rio Grande County


Routt County 107 Steamboat Springs 1877-01-29 Split from Grand County. Named in honor of John Long Routt, the first Governor of the State of Colorado. &&&&&&&&&&023509.&&&&&023,509 &&&&&&&&&&&02362.1100002,362.11 sq mi
(&&&&&&&&&&&06118.&&&&&06,118 km²)
State map highlighting Routt County


Saguache County 109 Saguache 1866-12-29 Split from Lake and Costilla counties. Name comes from a Ute language noun meaning "sand dunes". &&&&&&&&&&&06108.&&&&&06,108 &&&&&&&&&&&03168.3200003,168.32 sq mi
(&&&&&&&&&&&08206.&&&&&08,206 km²)
State map highlighting Saguache County


San Juan County 111 Silverton 1876-01-31 Split from Lake County. Named for the San Juan River and San Juan Mountains, which in turn were named for Saint John the Evangelist. &&&&&&&&&&&&0699.&&&&&0699 &&&&&&&&&&&&0388.990000388.99 sq mi
(&&&&&&&&&&&01007.&&&&&01,007 km²)
State map highlighting San Juan County


San Miguel County 113 Telluride 1883-03-02 Split from San Juan County. Named for the San Miguel River and San Miguel Mountains, which in turn were named for Saint Michael the Archangel. &&&&&&&&&&&07359.&&&&&07,359 &&&&&&&&&&&01290.7600001,290.76 sq mi
(&&&&&&&&&&&03343.&&&&&03,343 km²)


Sedgwick County 115 Julesburg 1889-04-09 Split from Logan County. Named for Fort Sedgwick, which, in turn, was named for U.S. Army General John Sedgwick (1813 - 1864). &&&&&&&&&&&02379.&&&&&02,379 &&&&&&&&&&&&0548.830000548.83 sq mi
(&&&&&&&&&&&01421.&&&&&01,421 km²)


Summit County 117 Breckenridge 1861-11-01 Created as one of the 17 original counties of the Territory of Colorado. Named for the many high mountain summits in the area. &&&&&&&&&&027994.&&&&&027,994 &&&&&&&&&&&&0618.920000618.92 sq mi
(&&&&&&&&&&&01603.&&&&&01,603 km²)
State map highlighting Summit County


Teller County 119 Cripple Creek 1899-03-23 Split from El Paso and Fremont counties. Named in honor of Henry Moore Teller, a U.S. Senator from Colorado and United States Secretary of the Interior. &&&&&&&&&&023350.&&&&&023,350 &&&&&&&&&&&&0558.580000558.58 sq mi
(&&&&&&&&&&&01447.&&&&&01,447 km²)
State map highlighting Teller County


Washington County 121 Akron 1887-02-09 Split from Weld County. Named in honor of George Washington (1732 - 1799), the first President of the United States. &&&&&&&&&&&04814.&&&&&04,814 &&&&&&&&&&&02522.9000002,522.90 sq mi
(&&&&&&&&&&&06534.&&&&&06,534 km²)


Weld County 123 Greeley 1861-11-01 Created as one of the 17 original counties of the Territory of Colorado. Named in honor of Lewis Ledyard Weld, the first Secretary of the Territory of Colorado. &&&&&&&&&0252825.&&&&&0252,825 &&&&&&&&&&&04013.8400004,013.84 sq mi
(&&&&&&&&&&010396.&&&&&010,396 km²)
State map highlighting Weld County


Yuma County 125 Wray 1889-03-15 Split from Washington County. Named for the Quechan (Yuma) Nation of Native Americans. &&&&&&&&&&010043.&&&&&010,043 &&&&&&&&&&&02369.6100002,369.61 sq mi
(&&&&&&&&&&&06137.&&&&&06,137 km²)

Table 2

Map of Colorado counties, labelled
An enlargeable map of the 64 counties of the state of Colorado

The following sortable table lists the 64 counties of the state of Colorado with the following information:

  1. The official name of the county,
  2. The International Committee for Information Technology Standards (INCITS) county code.
  3. The date the county was established,
  4. The county seat,
  5. The rank among the 64 counties of Colorado by population as of July 1, 2013, as estimated by the United States Census Bureau,
  6. The county population as of July 1, 2013, as estimated by the United States Census Bureau,
  7. The county population as of April 1, 2010, as enumerated by the 2010 United States Census,
  8. The percent population change from April 1, 2010, to July 1, 2013,
  9. A link to a detailed transportation map of the county.
  10. The average population density per land area of the county as of July 1, 2012,
  11. The land area of the county,
  12. The water area of the county,
  13. The total area of the county,
  14. The maximum surface elevation in the county,
  15. The minimum surface elevation in the county,
  16. The reference latitude of the county, and
  17. The reference longitude of the county.
The 64 Counties of the State of Colorado

County INCITS Date Established County Seat Pop Rank 2013 Pop 2010 Census Pop Change Map Pop Density Land Area Water Area Total Area Max Elev Min Elev Latitude Longitude
Adams County 08001 1902-11-15 Brighton &&&&&&&&&&&&&&05.&&&&&05 469,193 441,603 &10000000000000006247693+6.25% map &10000000000000006000000393.6 mi−2
152.0 km−2
&100000000000000390000001,167.653 mi2
3,024.208 km2
&1000000000000000800000016.243 mi2
42.070 km2
&100000000000000390000001,183.897 mi2
3,066.278 km2
&100000000000000500000005,668 ft
1728 m
&100000000000000440000004,432 ft
1351 m
39.87° N 104.33° W
Alamosa County 08003 1913-03-08 Alamosa &&&&&&&&&&&&&029.&&&&&029 16,253 15,445 &10000000000000005231466+5.23% map &1000000000000002200000021.4 mi−2
8.3 km−2
&10000000000000053000000722.643 mi2
1,871.637 km2
&100000000000000580000000.698 mi2
1.808 km2
&10000000000000053000000723.341 mi2
1,873.445 km2
&1000000000000000300000014,351 ft
4374 m
&100000000000000100000006,387 ft
1947 m
37.57° N 105.79° W
Arapahoe County 08005 1861-11-01 Littleton &&&&&&&&&&&&&&03.&&&&&03 607,070 572,003 &10000000000000006130562+6.13% map &10000000000000003000000716.7 mi−2
276.7 km−2
&10000000000000048000000798.100 mi2
2,067.070 km2
&100000000000000220000007.337 mi2
19.004 km2
&10000000000000048000000805.438 mi2
2,086.074 km2
&100000000000000460000006,218 ft
1895 m
&100000000000000330000004,730 ft
1442 m
39.64° N 104.33° W
Archuleta County 08007 1885-04-14 Pagosa Springs &&&&&&&&&&&&&036.&&&&&036 12,194 12,084 &10000000000000000910294+0.91% map &100000000000000340000008.9 mi−2
3.5 km−2
&100000000000000330000001,350.175 mi2
3,496.938 km2
&100000000000000320000005.339 mi2
13.828 km2
&100000000000000330000001,355.514 mi2
3,510.765 km2
&1000000000000002600000013,308 ft
4056 m
&100000000000000140000006,085 ft
1855 m
37.20° N 107.05° W
Baca County 08009 1889-04-16 Springfield &&&&&&&&&&&&&055.&&&&&055 3,682 3,788 Template:Number table sorting/negative−2.80% map &100000000000000590000001.5 mi−2
0.6 km−2
&100000000000000110000002,554.967 mi2
6,617.334 km2
&100000000000000410000002.372 mi2
6.142 km2
&100000000000000110000002,557.338 mi2
6,623.476 km2
&100000000000000530000005,293 ft
1613 m
&100000000000000610000003,458 ft
1054 m
37.30° N 102.54° W
Bent County 08011 1870-02-11 Las Animas &&&&&&&&&&&&&047.&&&&&047 5,688 6,499 Template:Number table sorting/negative−12.48% map &100000000000000460000004.3 mi−2
1.7 km−2
&100000000000000320000001,512.861 mi2
3,918.292 km2
&1000000000000000300000028.222 mi2
73.094 km2
&100000000000000310000001,541.083 mi2
3,991.386 km2
&100000000000000590000004,857 ft
1481 m
&100000000000000570000003,671 ft
1119 m
37.93° N 103.08° W
Boulder County 08013 1861-11-01 Boulder &&&&&&&&&&&&&&07.&&&&&07 310,048 294,567 &10000000000000005255510+5.26% map &10000000000000005000000405.6 mi−2
156.6 km−2
&10000000000000052000000726.289 mi2
1,881.080 km2
&1000000000000000900000014.081 mi2
36.469 km2
&10000000000000051000000740.370 mi2
1,917.549 km2
&1000000000000001300000014,259 ft
4346 m
&100000000000000340000004,717 ft
1438 m
40.09° N 105.40° W
City and County of Broomfield 08014 2001-11-15 Broomfield &&&&&&&&&&&&&012.&&&&&012 59,471 55,889 &10000000000000006409132+6.41% map &100000000000000020000001,691.9 mi−2
653.2 km−2
&1000000000000006400000033.034 mi2
85.558 km2
&100000000000000600000000.566 mi2
1.466 km2
&1000000000000006400000033.600 mi2
87.024 km2
&100000000000000480000005,848 ft
1783 m
&100000000000000360000004,691 ft
1430 m
39.95° N 105.05° W
Chaffee County 08015 1879-02-10 Salida &&&&&&&&&&&&&027.&&&&&027 18,510 17,809 &10000000000000003936212+3.94% map &1000000000000002700000017.6 mi−2
6.8 km−2
&100000000000000430000001,013.403 mi2
2,624.702 km2
&100000000000000500000001.550 mi2
4.013 km2
&100000000000000430000001,014.953 mi2
2,628.716 km2
&1000000000000000200000014,427 ft
4397 m
&100000000000000200000005,298 ft
1615 m
38.74° N 106.32° W
Cheyenne County 08017 1889-03-25 Cheyenne Wells &&&&&&&&&&&&&059.&&&&&059 1,890 1,836 &10000000000000002941176+2.94% map &100000000000000600000001.0 mi−2
0.4 km−2
&100000000000000240000001,778.276 mi2
4,605.713 km2
&100000000000000360000003.153 mi2
8.166 km2
&100000000000000250000001,781.429 mi2
4,613.879 km2
&100000000000000550000005,257 ft
1602 m
&100000000000000550000003,740 ft
1140 m
38.84° N 102.60° W
Clear Creek County 08019 1861-11-01 Georgetown &&&&&&&&&&&&&039.&&&&&039 9,031 9,088 Template:Number table sorting/negative−0.63% map &1000000000000002000000023.0 mi−2
8.9 km−2
&10000000000000059000000395.227 mi2
1,023.633 km2
&100000000000000530000001.266 mi2
3.280 km2
&10000000000000059000000396.493 mi2
1,026.913 km2
&1000000000000001100000014,278 ft
4352 m
&100000000000000230000005,075 ft
1547 m
39.69° N 105.67° W
Conejos County 08021 1861-11-07 Conejos &&&&&&&&&&&&&040.&&&&&040 8,277 8,256 &10000000000000000254360+0.25% map &100000000000000410000006.4 mi−2
2.5 km−2
&100000000000000340000001,287.391 mi2
3,334.326 km2
&100000000000000340000003.566 mi2
9.235 km2
&100000000000000350000001,290.956 mi2
3,343.561 km2
&1000000000000003000000013,179 ft
4017 m
&100000000000000060000007,404 ft
2257 m
37.21° N 106.18° W
Costilla County 08023 1861-11-01 San Luis &&&&&&&&&&&&&056.&&&&&056 3,518 3,524 Template:Number table sorting/negative−0.17% map &100000000000000520000002.9 mi−2
1.1 km−2
&100000000000000380000001,226.952 mi2
3,177.790 km2
&100000000000000350000003.409 mi2
8.829 km2
&100000000000000380000001,230.360 mi2
3,186.619 km2
&1000000000000000400000014,351 ft
4374 m
&100000000000000070000007,375 ft
2248 m
37.28° N 105.43° W
Crowley County 08025 1911-05-29 Ordway &&&&&&&&&&&&&050.&&&&&050 5,322 5,823 Template:Number table sorting/negative−8.60% map &100000000000000380000007.4 mi−2
2.9 km−2
&10000000000000049000000787.421 mi2
2,039.411 km2
&1000000000000001100000012.908 mi2
33.430 km2
&10000000000000049000000800.329 mi2
2,072.842 km2
&100000000000000560000005,228 ft
1593 m
&100000000000000500000003,966 ft
1209 m
38.32° N 103.79° W
Custer County 08027 1877-03-09 Westcliffe &&&&&&&&&&&&&054.&&&&&054 4,285 4,255 &10000000000000000705052+0.71% map &100000000000000420000005.8 mi−2
2.2 km−2
&10000000000000051000000738.625 mi2
1,913.031 km2
&100000000000000520000001.299 mi2
3.365 km2
&10000000000000052000000739.925 mi2
1,916.396 km2
&1000000000000001500000014,246 ft
4342 m
&100000000000000410000004,547 ft
1386 m
38.10° N 105.37° W
Delta County 08029 1883-02-11 Delta &&&&&&&&&&&&&018.&&&&&018 30,483 30,952 Template:Number table sorting/negative−1.52% map &1000000000000001900000027.1 mi−2
10.5 km−2
&100000000000000400000001,142.050 mi2
2,957.897 km2
&100000000000000260000006.549 mi2
16.961 km2
&100000000000000400000001,148.599 mi2
2,974.858 km2
&1000000000000004000000011,396 ft
3474 m
&100000000000000320000004,763 ft
1452 m
38.86° N 107.86° W
City and County of Denver 08031 1902-11-15 Denver &&&&&&&&&&&&&&02.&&&&&02 649,495 600,158 &10000000000000008220668+8.22% map &100000000000000010000003,922.6 mi−2
1,514.5 km−2
&10000000000000062000000153.000 mi2
396.269 km2
&100000000000000490000001.631 mi2
4.225 km2
&10000000000000062000000154.632 mi2
400.494 km2
&100000000000000490000005,688 ft
1734 m
&100000000000000310000004,803 ft
1464 m
39.76° N 104.88° W
Dolores County 08033 1881-03-04 Dove Creek &&&&&&&&&&&&&058.&&&&&058 2,029 2,064 Template:Number table sorting/negative−1.70% map &100000000000000550000001.9 mi−2
0.7 km−2
&100000000000000420000001,067.051 mi2
2,763.650 km2
&100000000000000540000001.049 mi2
2.716 km2
&100000000000000420000001,068.100 mi2
2,766.366 km2
&1000000000000001400000014,252 ft
4344 m
&100000000000000290000004,911 ft
1497 m
37.75° N 108.53° W
Douglas County 08035 1861-11-01 Castle Rock &&&&&&&&&&&&&&08.&&&&&08 305,963 285,465 &10000000000000007180565+7.18% map &10000000000000007000000339.7 mi−2
131.2 km−2
&10000000000000047000000840.248 mi2
2,176.232 km2
&100000000000000390000002.621 mi2
6.789 km2
&10000000000000047000000842.869 mi2
2,183.022 km2
&100000000000000430000009,836 ft
2998 m
&100000000000000210000005,242 ft
1598 m
39.33° N 104.93° W
Eagle County 08037 1883-02-11 Eagle &&&&&&&&&&&&&015.&&&&&015 52,460 52,197 &10000000000000000503860+0.50% map &1000000000000001600000031.0 mi−2
12.0 km−2
&100000000000000270000001,684.530 mi2
4,362.912 km2
&100000000000000230000007.261 mi2
18.806 km2
&100000000000000270000001,691.791 mi2
4,381.718 km2
&1000000000000002000000014,011 ft
4271 m
&100000000000000130000006,220 ft
1896 m
39.63° N 106.69° W
Elbert County 08039 1874-02-02 Kiowa &&&&&&&&&&&&&022.&&&&&022 23,733 23,086 &10000000000000002802564+2.80% map &1000000000000003100000012.5 mi−2
4.8 km−2
&100000000000000210000001,850.847 mi2
4,793.671 km2
&100000000000000630000000.171 mi2
0.442 km2
&100000000000000220000001,851.018 mi2
4,794.113 km2
&100000000000000440000007,374 ft
2248 m
&100000000000000380000004,580 ft
1396 m
39.31° N 104.12° W
El Paso County 08041 1861-11-01 Colorado Springs &&&&&&&&&&&&&&01.&&&&&01 655,044 622,263 &10000000000000005268029+5.27% map &10000000000000008000000292.6 mi−2
113.0 km−2
&100000000000000190000002,126.801 mi2
5,508.390 km2
&100000000000000370000002.746 mi2
7.112 km2
&100000000000000190000002,129.547 mi2
5,515.501 km2
&1000000000000001700000014,115 ft
4302 m
&100000000000000250000005,055 ft
1541 m
38.83° N 104.53° W
Fremont County 08043 1861-11-01 Cañon City &&&&&&&&&&&&&016.&&&&&016 46,451 46,824 Template:Number table sorting/negative−0.80% map &1000000000000001700000030.5 mi−2
11.8 km−2
&100000000000000310000001,533.068 mi2
3,970.627 km2
&100000000000000560000000.863 mi2
2.235 km2
&100000000000000320000001,533.931 mi2
3,972.863 km2
&1000000000000003100000013,110 ft
3996 m
&100000000000000390000004,573 ft
1394 m
38.46° N 105.42° W
Garfield County 08045 1883-02-10 Glenwood Springs &&&&&&&&&&&&&013.&&&&&013 57,302 56,389 &10000000000000001619110+1.62% map &1000000000000002400000019.1 mi−2
7.4 km−2
&100000000000000080000002,947.563 mi2
7,634.154 km2
&100000000000000180000008.274 mi2
21.431 km2
&100000000000000080000002,955.838 mi2
7,655.584 km2
&1000000000000003400000012,361 ft
3768 m
&100000000000000420000004,471 ft
1363 m
39.60° N 107.91° W
Gilpin County 08047 1861-11-01 Central City &&&&&&&&&&&&&048.&&&&&048 5,601 5,441 &10000000000000002940635+2.94% map &1000000000000001500000036.3 mi−2
14.0 km−2
&10000000000000063000000149.896 mi2
388.229 km2
&100000000000000620000000.364 mi2
0.942 km2
&10000000000000063000000150.260 mi2
389.171 km2
&1000000000000002700000013,300 ft
4054 m
&100000000000000280000004,983 ft
1519 m
39.86° N 105.53° W
Grand County 08049 1874-02-02 Hot Sulphur Springs &&&&&&&&&&&&&033.&&&&&033 14,289 14,843 Template:Number table sorting/negative−3.73% map &100000000000000360000008.0 mi−2
3.1 km−2
&100000000000000220000001,846.330 mi2
4,781.972 km2
&1000000000000000400000023.263 mi2
60.250 km2
&100000000000000210000001,869.592 mi2
4,842.222 km2
&1000000000000002500000013,559 ft
4133 m
&100000000000000150000006,040 ft
1841 m
40.12° N 106.10° W
Gunnison County 08051 1877-03-09 Gunnison &&&&&&&&&&&&&031.&&&&&031 15,507 15,324 &10000000000000001194205+1.19% map &100000000000000440000004.7 mi−2
1.8 km−2
&100000000000000050000003,239.099 mi2
8,389.229 km2
&1000000000000000500000020.530 mi2
53.172 km2
&100000000000000050000003,259.629 mi2
8,442.401 km2
&1000000000000000900000014,279 ft
4352 m
&100000000000000090000007,178 ft
2188 m
38.67° N 107.08° W
Hinsdale County 08053 1874-02-10 Lake City &&&&&&&&&&&&&062.&&&&&062 813 843 Template:Number table sorting/negative−3.56% map &100000000000000640000000.8 mi−2
0.3 km−2
&100000000000000410000001,117.251 mi2
2,893.668 km2
&100000000000000300000005.917 mi2
15.325 km2
&100000000000000410000001,123.168 mi2
2,908.992 km2
&1000000000000000600000014,321 ft
4365 m
&100000000000000080000007,299 ft
2225 m
37.81° N 107.38° W
Huerfano County 08055 1861-11-01 Walsenburg &&&&&&&&&&&&&045.&&&&&045 6,519 6,711 Template:Number table sorting/negative−2.86% map &100000000000000480000004.2 mi−2
1.6 km−2
&100000000000000300000001,591.001 mi2
4,120.673 km2
&100000000000000420000002.236 mi2
5.792 km2
&100000000000000300000001,593.237 mi2
4,126.465 km2
&1000000000000000500000014,326 ft
4366 m
&100000000000000430000004,445 ft
1355 m
37.69° N 104.96° W
Jackson County 08057 1909-05-05 Walden &&&&&&&&&&&&&061.&&&&&061 1,365 1,394 Template:Number table sorting/negative−2.08% map &100000000000000610000000.9 mi−2
0.3 km−2
&100000000000000290000001,613.723 mi2
4,179.523 km2
&100000000000000240000007.239 mi2
18.750 km2
&100000000000000290000001,620.962 mi2
4,198.273 km2
&1000000000000003300000012,954 ft
3948 m
&100000000000000300000004,865 ft
1483 m
40.66° N 106.33° W
Jefferson County 08059 1861-11-01 Golden &&&&&&&&&&&&&&04.&&&&&04 551,798 534,543 &10000000000000003227991+3.23% map &10000000000000004000000699.5 mi−2
270.1 km−2
&10000000000000050000000764.208 mi2
1,979.290 km2
&100000000000000160000009.825 mi2
25.446 km2
&10000000000000050000000774.033 mi2
2,004.736 km2
&1000000000000003800000011,589 ft
3532 m
&100000000000000270000004,986 ft
1520 m
39.59° N 105.25° W
Kiowa County 08061 1889-04-11 Eads &&&&&&&&&&&&&060.&&&&&060 1,423 1,398 &10000000000000001788268+1.79% map &100000000000000630000000.8 mi−2
0.3 km−2
&100000000000000250000001,767.767 mi2
4,578.496 km2
&1000000000000000600000018.160 mi2
47.033 km2
&100000000000000240000001,785.927 mi2
4,625.529 km2
&100000000000000610000004,697 ft
1432 m
&100000000000000560000003,687 ft
1124 m
38.39° N 102.76° W
Kit Carson County 08063 1889-04-11 Burlington &&&&&&&&&&&&&041.&&&&&041 8,037 8,270 Template:Number table sorting/negative−2.82% map &100000000000000490000003.8 mi−2
1.5 km−2
&100000000000000180000002,160.822 mi2
5,596.502 km2
&100000000000000550000000.869 mi2
2.252 km2
&100000000000000180000002,161.691 mi2
5,598.754 km2
&100000000000000520000005,297 ft
1615 m
&100000000000000590000003,523 ft
1074 m
39.31° N 102.60° W
Lake County 08065 1861-11-01 Leadville &&&&&&&&&&&&&043.&&&&&043 7,306 7,310 Template:Number table sorting/negative−0.05% map &1000000000000002300000019.4 mi−2
7.5 km−2
&10000000000000061000000376.911 mi2
976.194 km2
&100000000000000250000006.998 mi2
18.124 km2
&10000000000000061000000383.909 mi2
994.319 km2
&1000000000000000100000014,440 ft
4401 m
&100000000000000010000008,720 ft
2658 m
39.20° N 106.35° W
La Plata County 08067 1874-02-10 Durango &&&&&&&&&&&&&014.&&&&&014 53,284 51,334 &10000000000000003798651+3.80% map &1000000000000001800000030.3 mi−2
11.7 km−2
&100000000000000260000001,692.078 mi2
4,382.463 km2
&100000000000000200000007.629 mi2
19.760 km2
&100000000000000260000001,699.708 mi2
4,402.223 km2
&1000000000000001800000014,093 ft
4296 m
&100000000000000480000004,268 ft
1301 m
37.29° N 107.84° W
Larimer County 08069 1861-11-01 Fort Collins &&&&&&&&&&&&&&06.&&&&&06 315,988 299,630 &10000000000000005459399+5.46% map &10000000000000009000000115.4 mi−2
44.6 km−2
&100000000000000090000002,596.002 mi2
6,723.613 km2
&1000000000000000100000037.952 mi2
98.295 km2
&100000000000000090000002,633.954 mi2
6,821.909 km2
&1000000000000002400000013,573 ft
4137 m
&100000000000000400000004,557 ft
1389 m
40.66° N 105.48° W
Las Animas County 08071 1866-02-09 Trinidad &&&&&&&&&&&&&032.&&&&&032 14,446 15,507 Template:Number table sorting/negative−6.84% map &100000000000000500000003.2 mi−2
1.3 km−2
&100000000000000010000004,772.671 mi2
12,361.162 km2
&100000000000000380000002.676 mi2
6.930 km2
&100000000000000010000004,775.347 mi2
12,368.092 km2
&1000000000000002300000013,631 ft
4155 m
&100000000000000460000004,317 ft
1316 m
37.32° N 104.04° W
Lincoln County 08073 1889-04-11 Hugo &&&&&&&&&&&&&049.&&&&&049 5,430 5,467 Template:Number table sorting/negative−0.68% map &100000000000000530000002.1 mi−2
0.8 km−2
&100000000000000100000002,577.626 mi2
6,676.021 km2
&100000000000000170000008.796 mi2
22.781 km2
&100000000000000100000002,586.422 mi2
6,698.802 km2
&100000000000000470000005,973 ft
1821 m
&100000000000000520000003,923 ft
1196 m
38.99° N 103.51° W
Logan County 08075 1887-02-25 Sterling &&&&&&&&&&&&&025.&&&&&025 22,450 22,709 Template:Number table sorting/negative−1.14% map &1000000000000003200000012.4 mi−2
4.8 km−2
&100000000000000230000001,838.546 mi2
4,761.813 km2
&100000000000000270000006.318 mi2
16.364 km2
&100000000000000230000001,844.864 mi2
4,778.177 km2
&100000000000000570000004,947 ft
1508 m
&100000000000000620000003,428 ft
1045 m
40.73° N 103.09° W
Mesa County 08077 1883-02-14 Grand Junction &&&&&&&&&&&&&011.&&&&&011 147,554 146,723 &10000000000000000566373+0.57% map &1000000000000001300000044.1 mi−2
17.0 km−2
&100000000000000040000003,328.974 mi2
8,622.003 km2
&1000000000000001200000012.149 mi2
31.467 km2
&100000000000000040000003,341.123 mi2
8,653.470 km2
&1000000000000004100000011,236 ft
3425 m
&100000000000000450000004,337 ft
1322 m
39.02° N 108.46° W
Mineral County 08079 1893-03-27 Creede &&&&&&&&&&&&&063.&&&&&063 721 712 &10000000000000001264044+1.26% map &100000000000000620000000.8 mi−2
0.3 km−2
&10000000000000046000000875.666 mi2
2,267.966 km2
&100000000000000430000002.016 mi2
5.222 km2
&10000000000000046000000877.683 mi2
2,273.188 km2
&1000000000000002100000013,902 ft
4237 m
&100000000000000030000007,549 ft
2301 m
37.65° N 106.93° W
Moffat County 08081 1911-02-27 Craig &&&&&&&&&&&&&034.&&&&&034 13,103 13,795 Template:Number table sorting/negative−5.02% map &100000000000000510000002.9 mi−2
1.1 km−2
&100000000000000020000004,743.290 mi2
12,285.065 km2
&100000000000000210000007.622 mi2
19.742 km2
&100000000000000020000004,750.912 mi2
12,304.807 km2
&1000000000000004200000010,840 ft
3304 m
&100000000000000260000004,993 ft
1522 m
40.57° N 108.20° W
Montezuma County 08083 1889-04-16 Cortez &&&&&&&&&&&&&021.&&&&&021 25,642 25,535 &10000000000000000419032+0.42% map &1000000000000003000000012.6 mi−2
4.9 km−2
&100000000000000200000002,029.527 mi2
5,256.451 km2
&1000000000000001500000010.624 mi2
27.517 km2
&100000000000000200000002,040.151 mi2
5,283.968 km2
&1000000000000002800000013,237 ft
4035 m
&100000000000000370000004,639 ft
1414 m
37.34° N 108.60° W
Montrose County 08085 1883-02-11 Montrose &&&&&&&&&&&&&017.&&&&&017 40,713 41,276 Template:Number table sorting/negative−1.36% map &1000000000000002500000018.4 mi−2
7.1 km−2
&100000000000000160000002,240.695 mi2
5,803.373 km2
&100000000000000460000001.901 mi2
4.923 km2
&100000000000000160000002,242.596 mi2
5,808.296 km2
&1000000000000003900000011,453 ft
3491 m
&100000000000000350000004,711 ft
1436 m
38.41° N 108.26° W
Morgan County 08087 1889-02-19 Fort Morgan &&&&&&&&&&&&&020.&&&&&020 28,404 28,159 &10000000000000000870059+0.87% map &1000000000000002100000022.0 mi−2
8.5 km−2
&100000000000000360000001,280.433 mi2
3,316.305 km2
&1000000000000001000000013.310 mi2
34.474 km2
&100000000000000340000001,293.743 mi2
3,350.779 km2
&100000000000000580000004,937 ft
1505 m
&100000000000000490000003,989 ft
1216 m
40.26° N 103.81° W
Otero County 08089 1889-03-25 La Junta &&&&&&&&&&&&&026.&&&&&026 18,703 18,831 Template:Number table sorting/negative−0.68% map &1000000000000002800000014.9 mi−2
5.8 km−2
&100000000000000370000001,261.961 mi2
3,268.465 km2
&100000000000000190000007.742 mi2
20.052 km2
&100000000000000370000001,269.704 mi2
3,288.518 km2
&100000000000000540000005,273 ft
1607 m
&100000000000000540000003,809 ft
1161 m
37.88° N 103.72° W
Ouray County 08091 1877-01-18 Ouray &&&&&&&&&&&&&052.&&&&&052 4,557 4,436 &10000000000000002727682+2.73% map &100000000000000350000008.2 mi−2
3.2 km−2
&10000000000000058000000541.593 mi2
1,402.719 km2
&100000000000000590000000.618 mi2
1.600 km2
&10000000000000058000000542.210 mi2
1,404.318 km2
&1000000000000001600000014,158 ft
4315 m
&100000000000000110000006,315 ft
1925 m
38.15° N 107.77° W
Park County 08093 1861-11-01 Fairplay &&&&&&&&&&&&&030.&&&&&030 16,121 16,206 Template:Number table sorting/negative−0.52% map &100000000000000390000007.4 mi−2
2.9 km−2
&100000000000000170000002,193.846 mi2
5,682.034 km2
&1000000000000000700000016.807 mi2
43.531 km2
&100000000000000170000002,210.653 mi2
5,725.565 km2
&1000000000000000800000014,293 ft
4357 m
&100000000000000170000005,826 ft
1776 m
39.12° N 105.72° W
Phillips County 08095 1889-03-27 Holyoke &&&&&&&&&&&&&053.&&&&&053 4,356 4,442 Template:Number table sorting/negative−1.94% map &100000000000000400000006.5 mi−2
2.5 km−2
&10000000000000054000000687.928 mi2
1,781.725 km2
&100000000000000640000000.117 mi2
0.302 km2
&10000000000000054000000688.044 mi2
1,782.027 km2
&100000000000000640000004,117 ft
1255 m
&100000000000000580000003,582 ft
1092 m
40.59° N 102.35° W
Pitkin County 08097 1881-02-23 Aspen &&&&&&&&&&&&&028.&&&&&028 17,379 17,148 &10000000000000001347095+1.35% map &1000000000000002600000017.7 mi−2
6.8 km−2
&10000000000000044000000970.697 mi2
2,514.094 km2
&100000000000000400000002.498 mi2
6.469 km2
&10000000000000044000000973.195 mi2
2,520.564 km2
&1000000000000001000000014,279 ft
4352 m
&100000000000000180000005,695 ft
1736 m
39.22° N 106.92° W
Prowers County 08099 1889-04-11 Lamar &&&&&&&&&&&&&035.&&&&&035 12,291 12,551 Template:Number table sorting/negative−2.07% map &100000000000000370000007.7 mi−2
3.0 km−2
&100000000000000280000001,638.394 mi2
4,243.422 km2
&100000000000000290000005.928 mi2
15.353 km2
&100000000000000280000001,644.322 mi2
4,258.775 km2
&100000000000000600000004,713 ft
1437 m
&100000000000000630000003,346 ft
1020 m
37.96° N 102.39° W
Pueblo County 08101 1861-11-01 Pueblo &&&&&&&&&&&&&010.&&&&&010 161,451 159,063 &10000000000000001501291+1.50% map &1000000000000001000000066.7 mi−2
25.7 km−2
&100000000000000130000002,386.104 mi2
6,179.981 km2
&1000000000000001300000011.691 mi2
30.280 km2
&100000000000000130000002,397.795 mi2
6,210.261 km2
&1000000000000003500000012,352 ft
3765 m
&100000000000000470000004,291 ft
1308 m
38.17° N 104.49° W
Rio Blanco County 08103 1889-03-25 Meeker &&&&&&&&&&&&&044.&&&&&044 6,807 6,666 &10000000000000002115211+2.12% map &100000000000000540000002.1 mi−2
0.8 km−2
&100000000000000060000003,220.933 mi2
8,342.179 km2
&100000000000000470000001.880 mi2
4.868 km2
&100000000000000060000003,222.813 mi2
8,347.047 km2
&1000000000000003700000012,033 ft
3668 m
&100000000000000240000005,062 ft
1543 m
39.97° N 108.20° W
Rio Grande County 08105 1874-02-10 Del Norte &&&&&&&&&&&&&037.&&&&&037 11,803 11,982 Template:Number table sorting/negative−1.49% map &1000000000000002900000013.1 mi−2
5.1 km−2
&10000000000000045000000911.958 mi2
2,361.960 km2
&100000000000000610000000.380 mi2
0.984 km2
&10000000000000045000000912.338 mi2
2,362.944 km2
&1000000000000002900000013,209 ft
4026 m
&100000000000000040000007,467 ft
2276 m
37.49° N 106.45° W
Routt County 08107 1877-01-29 Steamboat Springs &&&&&&&&&&&&&023.&&&&&023 23,513 23,509 &10000000000000000017014+0.02% map &1000000000000003300000010.0 mi−2
3.8 km−2
&100000000000000150000002,362.026 mi2
6,117.619 km2
&100000000000000280000006.110 mi2
15.826 km2
&100000000000000150000002,368.136 mi2
6,133.445 km2
&1000000000000003600000012,185 ft
3714 m
&100000000000000120000006,266 ft
1910 m
40.48° N 106.99° W
Saguache County 08109 1866-12-29 Saguache &&&&&&&&&&&&&046.&&&&&046 6,208 6,108 &10000000000000001637197+1.64% map &100000000000000560000001.9 mi−2
0.7 km−2
&100000000000000070000003,168.524 mi2
8,206.441 km2
&100000000000000480000001.720 mi2
4.455 km2
&100000000000000070000003,170.244 mi2
8,210.895 km2
&1000000000000000700000014,300 ft
4359 m
&100000000000000160000006,013 ft
1833 m
38.03° N 106.25° W
San Juan County 08111 1876-01-31 Silverton &&&&&&&&&&&&&064.&&&&&064 692 699 Template:Number table sorting/negative−1.00% map &100000000000000580000001.8 mi−2
0.7 km−2
&10000000000000060000000387.488 mi2
1,003.588 km2
&100000000000000570000000.786 mi2
2.036 km2
&10000000000000060000000388.274 mi2
1,005.624 km2
&1000000000000002200000013,900 ft
4237 m
&100000000000000020000007,683 ft
2342 m
37.78° N 107.67° W
San Miguel County 08113 1883-03-02 Telluride &&&&&&&&&&&&&042.&&&&&042 7,678 7,359 &10000000000000004334828+4.33% map &100000000000000430000005.7 mi−2
2.2 km−2
&100000000000000350000001,286.611 mi2
3,332.308 km2
&100000000000000440000002.013 mi2
5.214 km2
&100000000000000360000001,288.625 mi2
3,337.522 km2
&1000000000000001900000014,023 ft
4274 m
&100000000000000190000005,308 ft
1618 m
38.01° N 108.43° W
Sedgwick County 08115 1889-04-09 Julesburg &&&&&&&&&&&&&057.&&&&&057 2,360 2,379 Template:Number table sorting/negative−0.80% map &100000000000000450000004.3 mi−2
1.7 km−2
&10000000000000057000000548.041 mi2
1,419.419 km2
&100000000000000510000001.363 mi2
3.531 km2
&10000000000000057000000549.404 mi2
1,422.950 km2
&100000000000000630000004,127 ft
1258 m
&100000000000000600000003,477 ft
1060 m
40.87° N 102.36° W
Summit County 08117 1861-11-01 Breckenridge &&&&&&&&&&&&&019.&&&&&019 28,649 27,994 &10000000000000002339787+2.34% map &1000000000000001200000046.0 mi−2
17.8 km−2
&10000000000000055000000608.358 mi2
1,575.639 km2
&1000000000000001400000010.920 mi2
28.283 km2
&10000000000000055000000619.278 mi2
1,603.922 km2
&1000000000000001200000014,278 ft
4352 m
&100000000000000050000007,460 ft
2274 m
39.62° N 106.14° W
Teller County 08119 1899-03-23 Cripple Creek &&&&&&&&&&&&&024.&&&&&024 23,275 23,350 Template:Number table sorting/negative−0.32% map &1000000000000001400000041.9 mi−2
16.2 km−2
&10000000000000056000000557.055 mi2
1,442.767 km2
&100000000000000450000001.909 mi2
4.945 km2
&10000000000000056000000558.965 mi2
1,447.712 km2
&1000000000000003200000013,065 ft
3982 m
&100000000000000220000005,236 ft
1596 m
38.87° N 105.18° W
Washington County 08121 1887-02-09 Akron &&&&&&&&&&&&&051.&&&&&051 4,803 4,814 Template:Number table sorting/negative−0.23% map &100000000000000570000001.9 mi−2
0.7 km−2
&100000000000000120000002,518.031 mi2
6,521.670 km2
&100000000000000310000005.872 mi2
15.207 km2
&100000000000000120000002,523.903 mi2
6,536.878 km2
&100000000000000510000005,433 ft
1656 m
&100000000000000530000003,910 ft
1192 m
39.97° N 103.21° W
Weld County 08123 1861-11-01 Greeley &&&&&&&&&&&&&&09.&&&&&09 269,785 252,825 &10000000000000006708197+6.71% map &1000000000000001100000063.4 mi−2
24.5 km−2
&100000000000000030000003,987.238 mi2
10,326.899 km2
&1000000000000000200000029.558 mi2
76.554 km2
&100000000000000030000004,016.796 mi2
10,403.453 km2
&100000000000000450000006,388 ft
1947 m
&100000000000000510000003,959 ft
1207 m
40.56° N 104.38° W
Yuma County 08125 1889-03-15 Wray &&&&&&&&&&&&&038.&&&&&038 10,151 10,043 &10000000000000001075375+1.08% map &100000000000000470000004.2 mi−2
1.6 km−2
&100000000000000140000002,364.405 mi2
6,123.780 km2
&100000000000000330000004.299 mi2
11.135 km2
&100000000000000140000002,368.704 mi2
6,134.915 km2
&100000000000000620000004,447 ft
1355 m
&100000000000000640000003,317 ft
1011 m
40.00° N 102.42° W
State of Colorado 08 1876-08-01 Denver 5,268,367 5,029,196 &10000000000000004755650+4.76% map &1000000000000009900000048.5 mi−2
18.7 km−2
103,641.884 mi2
268,431.246 km2
451.779 mi2
1,170.101 km2
104,093.662 mi2
269,601.348 km2
14,440 ft
4401 m
3,317 ft
1011 m
38.99° N 105.51° W

County high points

Former counties

The sortable table below lists all the historic counties of the Territory of New Mexico, the Territory of Utah, the Territory of Kansas, and the extralegal Territory of Jefferson that previously existed within the boundaries of the present State of Colorado, as well as the three defunct counties of the Territory of Colorado and the three defunct counties of the State of Colorado. The table includes the following information:

  1. The official name of the county,
  2. The territory or state,
  3. The date the county was created,
  4. The date the county was abolished or excluded from the new Territory of Colorado, and
  5. Historical notes.
Counties formerly within the area of the State of Colorado

County Territory or State Created Superseded History
Taos County Territory of New Mexico 185201091852-01-09 186102281861-02-28 Originally one of the seven partidos of the Spanish, and later Mexican, province of Santa Fe de Nuevo México. One of the nine original counties created by the Territory of New Mexico in 1852. Excluded from the new Territory of Colorado in 1861.
Great Salt Lake County Territory of Utah 185203031852-03-03 186102281861-02-28 Created in 1852, and excluded from the new Territory of Colorado in 1861.
Green River County Territory of Utah 185203031852-03-03 186102281861-02-28 Created in 1852, but never organized. Dissolved in 1857, but recreated in 1859. Excluded from the new Territory of Colorado in 1861, and the Territory of Wyoming in 1868. Finally dissolved in 1872.
Iron County Territory of Utah 185203031852-03-03 186102281861-02-28 Created in 1852, and excluded from the new Territory of Colorado in 1861.
Sanpete County Territory of Utah 185203031852-03-03 186102281861-02-28 Created in 1852, and excluded from the new Territory of Colorado in 1861.
Utah County Territory of Utah 185203031852-03-03 186102281861-02-28 Created in 1852, and excluded from the new Territory of Colorado in 1861.
Washington County Territory of Utah 185203031852-03-03 186102281861-02-28 Created in 1852, and excluded from the new Territory of Colorado in 1861.
Arapahoe County Territory of Kansas 185508251855-08-25 186101291861-01-29 Created in 1855, but never organized. Reverted to unorganized territory when Kansas joined the Union in 1861.
Beaver County Territory of Utah 185601051856-01-05 186102281861-02-28 Split from Iron and Millard counties in 1856. Excluded from the new Territory of Colorado in 1861.
Broderick County Territory of Kansas 185902071859-02-07 186101291861-01-29 Split from Arapahoe County in 1859, but never organized. Reverted to unorganized territory when Kansas joined the Union in 1861.
El Paso County Territory of Kansas 185902071859-02-07 186101291861-01-29 Split from Arapahoe County in 1859, but never organized. Reverted to unorganized territory when Kansas joined the Union in 1861.
Fremont County Territory of Kansas 185902071859-02-07 186101291861-01-29 Split from Arapahoe County in 1859, but never organized. Reverted to unorganized territory when Kansas joined the Union in 1861.
Montana County Territory of Kansas 185902071859-02-07 186101291861-01-29 Split from Arapahoe County in 1859, but never organized. Reverted to unorganized territory when Kansas joined the Union in 1861.
Oro County Territory of Kansas 185902071859-02-07 186101291861-01-29 Split from Arapahoe County in 1859, but never organized. Reverted to unorganized territory when Kansas joined the Union in 1861.
Peketon County Territory of Kansas 185902071859-02-07 186101291861-01-29 Created in 1859, but never organized. Reverted to unorganized territory when Kansas joined the Union in 1861.
Arrappahoe County Territory of Jefferson 185911281859-11-28 186102281861-02-28 One of the 12 counties created by the extralegal Territory of Jefferson in 1859.
Cheyenne County Territory of Jefferson 185911281859-11-28 186102281861-02-28 One of the 12 counties created by the extralegal Territory of Jefferson in 1859.
El Paso County Territory of Jefferson 185911281859-11-28 186102281861-02-28 One of the 12 counties created by the extralegal Territory of Jefferson in 1859.
Fountain County Territory of Jefferson 185911281859-11-28 186102281861-02-28 One of the 12 counties created by the extralegal Territory of Jefferson in 1859.
Heele County Territory of Jefferson 185911281859-11-28 186102281861-02-28 One of the 12 counties created by the extralegal Territory of Jefferson in 1859.
Jackson County Territory of Jefferson 185911281859-11-28 186102281861-02-28 One of the 12 counties created by the extralegal Territory of Jefferson in 1859.
Jefferson County Territory of Jefferson 185911281859-11-28 186102281861-02-28 One of the 12 counties created by the extralegal Territory of Jefferson in 1859.
Mountain County Territory of Jefferson 185911281859-11-28 186102281861-02-28 One of the 12 counties created by the extralegal Territory of Jefferson in 1859.
North County Territory of Jefferson 185911281859-11-28 186102281861-02-28 One of the 12 counties created by the extralegal Territory of Jefferson in 1859.
Park County Territory of Jefferson 185911281859-11-28 186102281861-02-28 One of the 12 counties created by the extralegal Territory of Jefferson in 1859.
Saint Vrain CountySt. Vrain County Territory of Jefferson 185911281859-11-28 186102281861-02-28 One of the 12 counties created by the extralegal Territory of Jefferson in 1859.
Saratoga County Territory of Jefferson 185911281859-11-28 186102281861-02-28 One of the 12 counties created by the extralegal Territory of Jefferson in 1859.
Mora County Territory of New Mexico 186002011860-02-01 186102281861-02-28 Split from Taos County and San Miguel County in 1860. Excluded from the new Territory of Colorado in 1861.
Guadalupe County Territory of Colorado 186111011861-11-01 186111071861-11-07 One of the 17 original counties created by the Territory of Colorado in 1861. The county was renamed Conejos County after only six days.
Greenwood County Territory of Colorado 187002111870-02-11 187402061874-02-06 Created from former Cheyenne and Arapaho tribal land and the eastern portion of Huerfano County in 1870. The county was abolished in 1874 and its territory split between Elbert County and Bent County.
Platte County Territory of Colorado 187202091872-02-09 187402091874-02-09 Created from the eastern portion of Weld County in 1872. The county was abolished in 1874 after organizers failed to secure voter approval. The territory of the county was returned to Weld County.
Carbonate County State of Colorado 187902081879-02-08 187902101879-02-10 Lake County was renamed Carbonate County in 1879. Only two days later, Carbonate County was split into the new Chaffee County and a recreated Lake County.
Uncompaghre County State of Colorado 188302271883-02-27 188303021883-03-02 Ouray County was renamed Uncompaghre County for only four days in 1883.
South Arapahoe County State of Colorado 190211151902-11-15 190304111903-04-11 One of three counties created from Arapahoe County in 1902. The name was changed back to Arapahoe County after five months.

No organized counties of the District of Louisiana, the Territory of Missouri, the extralegal State of Deseret, or the Territory of Nebraska existed within the present boundaries of the state of Colorado.

County distinctions

1. Costilla County 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, created by the Territory 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 created 12 counties:
The 12 counties of the
Territory of Jefferson
County County Seat
Arrappahoe County Denver City
Cheyenne County
El Paso County Colorado City
Fountain County Pueblo
Heele County La Porte
Jackson County Boulder City
Jefferson County Arapahoe City
Golden City
Mountain County Central City
North County
Park County Tarryall City
Saint Vrain's CountySt. Vrain's County Saint VrainSt. Vrain
Saratoga County Breckinridge
5. On November 1, 1861, the Territory of Colorado created the 17 original Colorado counties:
The 17 original counties of the
Territory of Colorado
County First County Seat
Arapahoe County Denver City
Boulder County Boulder City
Clear Creek County Idaho
Costilla County San Miguel
Douglas County Franktown
El Paso County Colorado City
Fremont County Cañon City
Gilpin County Central City
Guadaloupe County Guadaloupe
Huerfano County Autobees
Jefferson County Golden City
Lake County Oro City
Larimer County La Porte
Park County Tarryall City
Pueblo County Pueblo
Summit County Parkville
Weld County Saint VrainSt. Vrain
6. Of the 17 original Colorado counties created in 1861, only Gilpin County and Clear Creek County have retained their original boundaries with only minor survey changes.
7. Guadalupe County was the first Colorado county to be renamed 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 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.
11. In 1877, Ouray County 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.
14. Las Animas County is the most extensive Colorado county.
15. The City and County of Broomfield is the least extensive Colorado county.
16. El Paso County is the most populous Colorado county.
17. San Juan County is the least populous Colorado county.
18. El Paso County and the City and County of Denver are among the 100 most populous counties of the United States.
19. San Juan County, Mineral County, Hinsdale County, Jackson County, Kiowa County, Cheyenne County, and Dolores County are among the 100 least populous counties of the United States.
20. The City and County of Denver is the most densely populated Colorado county.
21. Hinsdale County is the least densely populated Colorado county.
22. Hinsdale County, Kiowa County, Mineral County, and Jackson County have fewer than one resident per square mile (0.386 km−2).
23. Lake County has the highest point in Colorado at the summit of Mount Elbert at 14,440 feet (4,401 m) elevation (the highest point in the entire Rocky Mountains).
24. Yuma County has the lowest point in Colorado where the Arikaree River flows into Kansas at 3,317 feet (1,011 m) elevation (the highest low point of any U.S. state).
25. Jefferson County borders ten other counties, the most of any Colorado county.
26. Delta County and the City and County of Denver each border only three other counties, the fewest of Colorado counties.
27. The following twelve Colorado counties have a county seat with the same name as the county:
County County Seat
Alamosa County City of Alamosa
Boulder County City of Boulder
BroomfieldCity and County of Broomfield City and County of Broomfield
Conejos County unincorporated town of Conejos
Delta County City of Delta
DenverCity and County of Denver City and County of Denver
Eagle County Town of Eagle
Gunnison County City of Gunnison
Montrose County City of Montrose
Ouray County City of Ouray
Pueblo County City of Pueblo
Saguache County Town of Saguache
28. The name of each of the following two Colorado counties forms one part of the name of its county seat:
County County Seat
Cheyenne County Town of Cheyenne Wells
Morgan County City of Fort Morgan
29. Weld County has the most incorporated municipalities of any Colorado county with 31.
30. The following nine Colorado counties have no incorporated municipalities other than their county seat:
County County Seat
Archuleta County Town of Pagosa Springs
Bent County City of Las Animas
BroomfieldCity and County of Broomfield City and County of Broomfield
DenverCity and County of Denver City and County of Denver
Hinsdale County Town of Lake City
Jackson County Town of Walden
Lake County City of Leadville
Mineral County Town of Creede
San Juan County Town of Silverton
31. Of all 64 Colorado counties, only Conejos County has a county seat that is not an incorporated municipality.
32. Only three Colorado county seats extend into other counties:
County County Seat Other Counties
Adams County City of Brighton Weld County
Arapahoe County City of Littleton Douglas County and Jefferson County
Gilpin County Central City Clear Creek County
33. The City and County of Denver and the City and County of Broomfield are the only two Colorado counties with enclaves.
34. Arapahoe County, Boulder County, and Jefferson County are the only three dismembered Colorado counties with exclaves.
35. San Juan County has the highest mean elevation of any U.S. county at 11,240 feet (3,426 m). The 25 highest U.S. counties by mean elevation are:
Highest Counties in the United States
Rank County State Mean Elevation
&&&&&&&&&&&&&&01.&&&&&01 San Juan County  Colorado 11,240 feet (3,426 m)
&&&&&&&&&&&&&&02.&&&&&02 Hinsdale County  Colorado 10,826 feet (3,300 m)
&&&&&&&&&&&&&&03.&&&&&03 Lake County  Colorado 10,790 feet (3,289 m)
&&&&&&&&&&&&&&04.&&&&&04 Mineral County  Colorado 10,411 feet (3,173 m)
&&&&&&&&&&&&&&05.&&&&&05 Summit County  Colorado 10,365 feet (3,159 m)
&&&&&&&&&&&&&&06.&&&&&06 Clear Creek County  Colorado 10,264 feet (3,128 m)
&&&&&&&&&&&&&&07.&&&&&07 Pitkin County  Colorado 9,940 feet (3,030 m)
&&&&&&&&&&&&&&08.&&&&&08 Chaffee County  Colorado 9,915 feet (3,022 m)
&&&&&&&&&&&&&&09.&&&&&09 Park County  Colorado 9,572 feet (2,918 m)
&&&&&&&&&&&&&010.&&&&&010 Gunnison County  Colorado 9,488 feet (2,892 m)
&&&&&&&&&&&&&011.&&&&&011 Gilpin County  Colorado 9,236 feet (2,815 m)
&&&&&&&&&&&&&012.&&&&&012 Grand County  Colorado 9,204 feet (2,805 m)
&&&&&&&&&&&&&013.&&&&&013 Saguache County  Colorado 9,193 feet (2,802 m)
&&&&&&&&&&&&&014.&&&&&014 Teller County  Colorado 9,052 feet (2,759 m)
&&&&&&&&&&&&&015.&&&&&015 Rio Grande County  Colorado 9,011 feet (2,747 m)
&&&&&&&&&&&&&016.&&&&&016 Custer County  Colorado 8,988 feet (2,740 m)
&&&&&&&&&&&&&017.&&&&&017 Eagle County  Colorado 8,987 feet (2,739 m)
&&&&&&&&&&&&&018.&&&&&018 Ouray County  Colorado 8,951 feet (2,728 m)
&&&&&&&&&&&&&019.&&&&&019 Jackson County  Colorado 8,863 feet (2,701 m)
&&&&&&&&&&&&&020.&&&&&020 Conejos County  Colorado 8,774 feet (2,674 m)
&&&&&&&&&&&&&021.&&&&&021 Costilla County  Colorado 8,681 feet (2,646 m)
&&&&&&&&&&&&&022.&&&&&022 Taos County  New Mexico 8,510 feet (2,594 m)
&&&&&&&&&&&&&023.&&&&&023 Summit County  Utah 8,388 feet (2,557 m)
&&&&&&&&&&&&&024.&&&&&024 Dolores County  Colorado 8,280 feet (2,524 m)
&&&&&&&&&&&&&025.&&&&&025 Archuleta County  Colorado 8,101 feet (2,469 m)

List of counties in Colorado Facts for Kids. Kiddle Encyclopedia.