Historical Facts of Colorado Counties

Colorado County records differ vastly from county to county both in quality and also quantity. Some have already been carefully preserved and some have been much abused and uncared for. Many Colorado records have simply vanished. For genealogists performing research in Colorado there is no valuable replace for an on-site research of county court house records. For Definitions of all court terms see the Genealogy Encyclopedia

Colorado Counties

Colorado is divided into 14 counties. Presumably, tax records for each county go back to the time at which each county was formed. However, that isn’t necessarily the case for every single county. So, it’s important to check the county in question. The Colorado State Archives is home to many of the earlier records for each county. Each county has a vital records office. Each of those may hold some of the vital records from the time before statewide recording took place. Probate records are located in the district courts, but court records may be found in district or county courts. Early county records for Colorado may be found at the Colorado State Archives.

Most land records are located at the county seat, along with most marriage records. The County Vital Records offices may also hold older vital records that predate statewide recording. Colorado State Government is located in Denver.

The links in the table below link to county and city government offices and is limited to government-maintained websites. If you know of a Colorado county that has an official government web site but is not linked, or if the link is in error, please contact us so we may edit our database.

County Date Formed Parent County County Seat
Adams April 15, 1861 Arapahoe County. Brighton
Alamosa March 08, 1913 Costilla  and Conejos  counties. Alamosa
Arapahoe November 01, 1861 Created as one of the 17 original counties of the Territory of Colorado Littleton
Archuleta April 14, 1885 Conejos County Pagosa Springs
Baca April 16, 1889 Las Animas County Springfield
Bent February 11, 1870 Huerfano County and former Cheyenne and Arapaho tribal land. Las Animas
Boulder November 01, 1861 Created as one of the 17 original counties of the Territory of Colorado. Boulder
Broomfield City & County November 15, 2001 Boulder, Adams, Jefferson, and Weld counties and reorganized as a consolidated city and county. Broomfield
Clear Creek February 10, 1879 Carbonate County. Georgetown
Chaffee March 25, 1889 Elbert and Bent counties. Salida
Cheyenne November 01, 1861 Created as one of the 17 original counties of the Territory of Colorado. Cheyenne Wells
Conejos November 01, 1861 Guadalupe County, one of the 17 original counties of theTerritory of Colorado, was renamed Conejos County after six days on November 7, 1861. Conejos
Costilla November 01, 1861 Created as one of the 17 original counties of the Territory of Colorado. San Luis
Crowley May 29, 1911 Otero County. Ordway
Custer March 09, 1877 Fremont County. Westcliffe
Delta February 11, 1883 Gunnison County. Delta
Denver City & County March 18, 1901 The original Arapahoe County Seat was split from Arapahoe County and reorganized as a consolidated city and county. Denver
Dolores February 19, 1881 Ouray County. Dove Creek
Douglas November 01, 1861 Created as one of the 17 original counties of the Territory of Colorado. Castle Rock
Eagle February 11, 1883 Summit County. Eagle
Elbert February 02, 1874 Douglas County. Kiowa
El Paso November 01, 1861 Created as one of the 17 original counties of the Territory of Colorado. Colorado Springs
Fremont November 01, 1861 Created as one of the 17 original counties of the Territory of Colorado. Cañon City
Garfield February 10, 1883 Summit County. Glenwood Springs
Gilpin November 01, 1861 Created as one of the 17 original counties of the Territory of Colorado. Central City
Grand February 02, 1874 Summit County. Hot Sulphur Springs
Gunnison March 09, 1877 Lake County. Gunnison
Hinsdale February 10, 1874 Lake, Conejos, and Costilla counties. Lake City
Huerfano November 01, 1861 Created as one of the 17 original counties of the Territory of Colorado. Walsenburg
Jackson May 05, 1909 Larimer County. Walden
Jefferson November 01, 1861 Created as one of the 17 original counties of the Territory of Colorado. Golden
Kiowa April 11, 1889 Bent County. Eads
Kit Carson April 11, 1889 Elbert County. Burlington
La Plata February 10, 1879 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. Durango
Lake February 10, 1874 Lake and Conejos counties. Leadville
Larimer November 01, 1861 Created as one of the 17 original counties of the Territory of Colorado. Fort Collins
Las Animas November 09, 1866 Huerfano County. Trinidad
Lincoln April 11, 1889 Elbert and Bent counties. Hugo
Logan February 02, 1887 Weld County. Sterling
Mesa February 14, 1883 Gunnison County. Grand Junction
Mineral March 27, 1893 Hinsdale, Rio Grande, and Saguache counties. Creede
Moffatt February 27, 1911 Routt County. Craig
Montezuma April 16, 1889 La Plata County. Cortez
Montrose February 11, 1883 Gunnison County. Montrose
Morgan February 19, 1889 Weld County. Fort Morgan
Otero February 19, 1889 Bent County. La Junta
Ouray March 02, 1883 Hinsdale and Lake counties. RenamedUncompaghre County for four days from 1883-02-27, to 1883-03-02. Ouray
Park November 01, 1861 Created as one of the 17 original counties of the Territory of Colorado. Fairplay
Phillips March 27, 1889 Logan County. Holyoke
Pitkin February 23, 1881 Gunnison County. Aspen
Prowers April 11, 1889 Bent County. Lamar
Pueblo November 01, 1861 Created as one of the 17 original counties of the Territory of Colorado. Pueblo
Rio Blanco March 25, 1889 Garfield County. Meeker
Rio Grande February 10, 1874 Costilla County and Conejos County counties. Del Norte
Routt January 29, 1877 Grand County. Steamboat Springs
Saguache December 29, 1866 Lake and Costilla counties. Saguache
San Juan January 31, 1876 Lake County. Silverton
San Miguel November 01, 1861 San Juan County. Telluride
Sedgwick April 09, 1889 Logan County. Julesburg
Summit November 01, 1861 Created as one of the 17 original counties of the Territory of Colorado. Breckenridge
Teller March 23, 1899 El Paso and Fremont counties. Cripple Creek
Washington February 09, 1887 Weld County. Akron
Weld November 01, 1861 Created as one of the 17 original counties of the Territory of Colorado. Greeley
Yuma March 15, 1889 Washington County. Wray


Interactive Map of Colorado Counties Formation

(Colorado maps made with the use AniMap Plus 3.0 & with the Permission of the Goldbug Company)

Colorado Extinct Counties

Colorado seems to have counties that no longer are in existence. They were established by the state, provincial, or territorial government. A lot of these counties were established and disbanded in the Nineteenth century; county boundaries have modified little since 1900 in the vast number of states. These counties need to be investigated when performing family history and genealogy research. Pay close attention where the courthouse records went to if the county was eliminated or merged with some other county.

  • Arapahoe County, Kansas Territory, (1855-08-25 – 1861-01-29) was created but never organized. Reverted to unorganized territory when Kansas joined the Union.
  • Broderick County, Kansas Territory, (1859-02-07 – 1861-01-29) was split from Arapahoe County, but never organized. Reverted to unorganized territory when Kansas joined the Union.
  • Carbonate County – was a county that existed for only two days in 1879. Carbonate County was created by renaming it to Lake County.
  • El Paso County, Kansas Territory, (1859-02-07 – 1861-01-29) was split from Arapahoe County, but never organized. Reverted to unorganized territory when Kansas joined the Union.
  • Fremont County, Kansas Territory, (1859-02-07 – 1861-01-29) was split from Arapahoe County, but never organized. Reverted to unorganized territory when Kansas joined the Union.
  • Montana County, Kansas Territory, (1859-02-07 – 1861-01-29) was split from Arapahoe County, but never organized. Reverted to unorganized territory when Kansas joined the Union.
  • Oro County, Kansas Territory, (1859-02-07 – 1861-01-29) was split from Arapahoe County, but never organized. Reverted to unorganized territory when Kansas joined the Union.
  • Peketon County, Kansas Territory, (1859-02-07 – 1861-01-29) was created but never organized. Reverted to unorganized territory when Kansas joined the Union.
  • Arrappahoe County, Jefferson Territory, (November 1859 – 1861-02-28) was one of the 12 counties created by the extralegal Territory of Jefferson.
  • Cheyenne County, Jefferson Territory, (November 1859 – 1861-02-28) was one of the 12 counties created by the extralegal Territory of Jefferson.
  • El Paso County, Jefferson Territory, (November 1859 – 1861-02-28) was one of the 12 counties created by the extralegal Territory of Jefferson.
  • Fountain County, Jefferson Territory, (November 1859 – 1861-02-28) was one of the 12 counties created by the extralegal Territory of Jefferson.
  • Heele County, Jefferson Territory, (November 1859 – 1861-02-28) was one of the 12 counties created by the extralegal Territory of Jefferson.
  • Jackson County, Jefferson Territory, (November 1859 – 1861-02-28) was one of the 12 counties created by the extralegal Territory of Jefferson.
  • Jefferson County, Jefferson Territory, (November 1859 – 1861-02-28) was one of the 12 counties created by the extralegal Territory of Jefferson.
  • Montana County, Jefferson Territory, (November 1859 – 1861-02-28) was one of the 12 counties created by the extralegal Territory of Jefferson.
  • North County, Jefferson Territory, (November 1859 – 1861-02-28) was one of the 12 counties created by the extralegal Territory of Jefferson.
  • Park County, Jefferson Territory, (November 1859 – 1861-02-28) was one of the 12 counties created by the extralegal Territory of Jefferson.
  • Saratoga County, Jefferson Territory, (November 1859 – 1861-02-28) was one of the 12 counties created by the extralegal Territory of Jefferson.
  • St. Vrains County, Jefferson Territory, (November 1859 – 1861-02-28) was one of the 12 counties created by the extralegal Territory of Jefferson.
  • Guadalupe County, Colorado Territory, (1861-11-01 – 1861-11-07) was one of the 17 original counties created by the Territory of Colorado. The county was renamed Conejos County after only six days.
  • Greenwood County, Colorado Territory, (1870-02-11 – 1874-02-06) was created from former Cheyenne and Arapaho tribal land and the eastern portion of Huerfano County. The county was abolished four years later, and its territory split between Elbert County and Bent County.
  • Platte County, Colorado Territory, (1872-02-09 – 1874-02-09) was created from the eastern portion of Weld County. The county was abolished two years later after organizers failed to secure voter approval, and the territory of the county was returned to Weld County.
  • Carbonate County, Colorado, (1879-02-08 – 1879-02-10). Lake County was renamed Carbonate County in 1879. Only two days later, Carbonate County was split into the new Chaffee County and the re-renamed Lake County.
  • Uncompaghre County, Colorado, (1883-02-27 – 1883-03-02). Ouray County was renamed Uncompaghre County for only four days in 1883.
  • South Arapahoe County, Colorado, (1902-11-15 – 1903-04-11) was one of three counties created from Arapahoe County in 1902. The name was changed back to Arapahoe County after five months.

Colorado Counties with Burned Courthouses

The destruction to Colorado courthouses tremendously has a impact on genealogists in just about every way. Not only are most of these historic structures torn from each of our lifetimes, so are the records they housed: marriage, wills, probate, land records, as well as others. Once destroyed they’re lost forever. Despite the fact that they have already been put on mircofilm, computers and film burn up as well. The most heartbreaking aspect of this is the reason that almost all of our courthouses are destroyed at the hands of arsonist. However, not all records were damaged or lost. Many Colorado counties have dealt with a loss of records due to courthouse fires, floods, and theft.

  • Conejos County Courthouse Some loss of records occurred by fire.
  • Douglas County Courthouse burned in 1978 but minimal loss of records.