List of county seats in Colorado

This is a list of the county seats of the U.S. State of Colorado and its two predecessors: the extralegal Territory of Jefferson and the official Territory of Colorado.

Territory of Jefferson
On August 24, 1859, voters of the Pike's Peak mining region approved the formation of the Provisional Government of the Territory of Jefferson and designated Denver City as the capital. On November 28, 1859, the territory established 12 counties which served as the de facto local government. The extralegal territory was unable to secure authorization from the United States Congress embroiled in the debate over slavery. On November 13, 1860, the territory moved its capital to Golden City. On February 28, 1861, after seven slave states seceded from the Union, U.S. President James Buchanan signed An Act to provide a temporary Government for the Territory of Colorado. On June 6, 1861, the Jefferson Territory officially yielded to the new Territory of Colorado.

The 12 counties of the Territory of Jefferson and their county seats

 * Arapahoe County†
 * Denver City (Territorial capital August 24, 1859, to November 13, 1860)
 * Cheyenne County†
 * No county seat designated.
 * El Paso County†
 * Colorado City
 * Fountain County†
 * Pueblo
 * Heele County†
 * La Porte
 * Jackson County†
 * Boulder City
 * Jefferson County†
 * Arapahoe City/Arapahoe – November 28, 1859, to November 6, 1860
 * Golden City – November 6, 1860, to June 6, 1861 (Territorial capital November 13, 1860, to June 6, 1861)
 * Mountain County†
 * Central City
 * North County†
 * No county seat designated.
 * Park County†
 * Tarryall City/Tarryall
 * St. Vrain's County†
 * Saint Vrain
 * Saratoga County†
 * Breckenridge/Breckinridge

Territory and State of Colorado
The free Territory of Colorado was officially organized on February 28, 1861. On November 1, 1861, the Colorado Territory 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 and Arapaho Reserve. The Colorado Territory later added 12 more counties for a total of 29, of which 26 still exist.

On August 1, 1876, U.S. President Ulysses S. Grant issued Proclamation 230: Admission of Colorado into the Union. The State of Colorado has created 41 counties of which 38 still exist, for a total of 64 existing counties.

The 64 current and six extinct counties of Colorado and their county seats

 * Adams County (November 15, 1902 to present)
 * Brighton
 * Alamosa County (March 8, 1913 to present)
 * Alamosa
 * Arapahoe County (November 1, 1861 to November 15, 1902; and  April 11, 1903, to present)
 * Denver City/Denver (Territorial capital February 28, 1861, to July 7, 1862, and December 9, 1867, to August 1, 1876; state capital since August 1, 1876)
 * Between November 15 and December 1, 1902, Arapahoe County was split into the City and County of Denver, Adams County; and South Arapahoe County. On April 11, 1903, the name of South Arapahoe County was changed back to Arapahoe County.
 * Littleton – April 11, 1903 to present
 * Archuleta County (April 14, 1885 to present)
 * Pagosa Springs
 * Baca County (April 16, 1889 to present)
 * Springfield
 * Bent County (February 11, 1870 to present)
 * Las Animas (east) – February 11, 1870 to 1870
 * Boggsville – 1870 to 1872
 * Las Animas (east) – 1872 to 1875
 * West Las Animas/Las Animas – 1875 to present
 * Boulder County (November 1, 1861 to present)
 * Boulder City/Boulder
 * City and County of Broomfield (November 15, 2001 to present)
 * Broomfield
 * Carbonate County† (February 8, 1879 to February 10, 1879)
 * Granite
 * Chaffee County (February 10, 1879 to present)
 * Granite – February 10, 1879 to 1888
 * Buena Vista – 1888 to 1928
 * Salida – 1928 to present
 * Cheyenne County (March 25, 1889 to present)
 * Cheyenne Wells
 * Clear Creek County (November 1, 1861 to present)
 * Idaho - November 1, 1861 to 1867
 * Georgetown – 1867 to present
 * Conejos County (November 7, 1861 to present)
 * Guadaloupe - November 7, 1861 to 1863
 * Conejos - 1863 to present
 * Costilla County (November 1, 1861 to present)
 * San Miguel/Costilla – November 1, 1861 to 1863
 * San Luis – 1863 to present
 * Crowley County (May 29, 1911 to present)
 * Ordway
 * Custer County (March 9, 1877 to present)
 * Ula – March 9, 1877 to 1878
 * Rosita – 1878 to 1886
 * Silver Cliff – 1886 to 1928
 * Westcliffe – 1928 to present
 * Delta County (February 11, 1883 to present)
 * Delta
 * City and County of Denver (December 1, 1902 to present)
 * Denver (State capital since August 1, 1876)
 * Dolores County (March 4, 1881 to present)
 * Rico – March 4, 1881 to 1945
 * Dove Creek – 1945 to present
 * Douglas County (November 1, 1861 to present)
 * Frankstown – November 1, 1861 to 1864
 * California Ranch/Franktown – 1864 to 1874
 * Castle Rock – 1874 to present
 * Eagle County (February 11, 1883 to present)
 * Red Cliff/Redcliff – February 11, 1883 to 1921
 * Eagle – 1921 to present
 * El Paso County (November 1, 1861 to present)
 * Colorado City – November 1, 1861 to 1873 (Territorial capital July 7, 1862, to August 14, 1862)
 * Colorado Springs – 1873 to present
 * Elbert County (February 2, 1874 to present)
 * Kiowa
 * Fremont County (November 1, 1861 to present)
 * Cañon City
 * Garfield County (February 10, 1883 to present)
 * Carbonate – February 10, 1883 to 1883
 * Barlow/Glenwood Springs – 1883 to present
 * Gilpin County (November 1, 1861 to present)
 * Central City
 * Grand County (February 2, 1874 to present)
 * Hot Sulphur Springs – February 2, 1874 to 1882
 * Grand Lake – 1882 to 1888
 * Hot Sulphur Springs/Sulphur Springs/Hot Sulphur Springs – 1888 to present
 * Greenwood County† (February 11, 1870 to February 6, 1874)
 * Kit Carson
 * Guadaloupe County† (November 1, 1861 until renamed Conejos County six days later)
 * Guadaloupe
 * Gunnison County (March 9, 1877 to present)
 * Gunnison
 * Hinsdale County (February 10, 1874 to present)
 * San Juan City/San Juan – February 10, 1874 to 1875
 * Lake City – 1875 to present
 * Huerfano County (November 1, 1861 to present)
 * Autobees Plaza – November 1, 1861 to 1868
 * Badito – 1868 to 1874
 * Walsenburgh/Tourist/Walsenburgh/Walsenburg – 1874 to present
 * Jackson County (May 5, 1909 to present)
 * Walden
 * Jefferson County (November 1, 1861 to present)
 * Golden City/Golden (Territorial capital August 14, 1862, to December 9, 1867)
 * Kiowa County (April 11, 1889 to present)
 * Sheridan Lake – April 11, 1889 to 1902
 * Eads – 1902 to present
 * Kit Carson County (April 11, 1889 to present)
 * Burlington
 * La Plata County (February 10, 1874 to present)
 * Howardsville – February 10, 1874 to January 31, 1876
 * Parrott City – January 31, 1876 to 1881
 * Durango – 1881 to present
 * Lake County (November 1, 1861 to February 8, 1879; and February 10, 1879, to present)
 * Oro City – November 1, 1861 to 1866
 * Dayton – 1866 to 1868
 * Granite – 1868 to February 8, 1879
 * Lake County was renamed Carbonate County for two days before being split into a new Chaffee County and a re-created Lake County.
 * Leadville – February 10, 1879 to present
 * Larimer County (November 1, 1861 to present)
 * La Porte – November 1, 1861 to 1868
 * Fort Collins – 1868 to present
 * Las Animas County (February 9, 1866 to present)
 * Trinidad
 * Lincoln County (April 11, 1889 to present)
 * Hugo
 * Logan County - February 25, 1887 to present)
 * Sterling
 * Mesa County (February 14, 1883 to present)
 * Grand Junction
 * Mineral County - (March 27, 1893 to present)
 * Wason – March 27, 1893 to November 7, 1893
 * Amethyst/Creede – November 7, 1893 to present
 * Moffat County (February 27, 1911 to present)
 * Craig
 * Montezuma County (April 16, 1889 to present)
 * Cortez
 * Montrose County (February 11, 1883 to present)
 * Montrose
 * Morgan County (February 19, 1889 to present)
 * Fort Morgan
 * Otero County (March 25, 1889 to present)
 * La Junta
 * Ouray County (January 18, 1877 to February 27, 1883; and March 2, 1883, to present)
 * Ouray
 * Park County (November 1, 1861 to present)
 * Tarryall – November 1, 1861 to January 7, 1862
 * Laurette/Bucksin/Buckskin Joe – January 7, 1862 to November 7, 1867
 * Fair Play/Fairplay – November 7, 1867 to present
 * Phillips County (March 27, 1889 to present)
 * Holyoke
 * Pitkin County (February 23, 1881 to present)
 * Aspen
 * Platte County† (February 9, 1872 to February 9, 1874)
 * Platte County failed to organize and reverted to the eastern portion of Weld County.
 * Prowers County (April 11, 1889 to present)
 * Lamar
 * Pueblo County (November 1, 1861 to present)
 * Pueblo
 * Rio Blanco County (March 25, 1889 to present)
 * Meeker
 * Rio Grande County (February 10, 1874 to present)
 * Del Norte
 * Routt County (January 29, 1877 to present)
 * Hayden – January 29, 1877 to 1878
 * Hahns Peak – 1878 to 1912
 * Steamboat Springs – 1912 to present
 * Saguache County (December 29, 1866 to present)
 * Saguache
 * San Juan County (January 31, 1876 to present)
 * Silverton
 * San Miguel County (March 2, 1883 to present)
 * Telluride
 * Sedgwick County (April 9, 1889 to present)
 * Julesburg
 * South Arapahoe County† (November 15, 1902 to April 11, 1903)
 * Littleton
 * Summit County (November 1, 1861 to present)
 * Parkville – November 1, 1861 to 1862
 * Breckenridge – 1862 to present
 * Teller County (March 23, 1899 to present)
 * Cripple Creek
 * Uncompahgre County† (February 27, 1883 to March 2, 1883)
 * Ouray
 * Washington County (February 9, 1887 to present)
 * Akron
 * Weld County (November 1, 1861 to present)
 * Saint Vrain – November 1, 1861 to 1868
 * Latham – 1868 to 1870
 * Evans – 1870 to 1874
 * Greeley – 1874 to 1875
 * Evans – 1875 to 1877
 * Greeley – 1877 to present
 * Yuma County (March 15, 1889 to present)
 * Yuma – March 15, 1889 to 1902
 * Wray – 1902 to present

County seat distinctions

 * 1) The five cities of Boulder, Cañon City, Central City, Golden, and Pueblo are the longest serving Colorado county seats having been designated by the Territory of Colorado on November 1, 1861.
 * 2) Of the 64 current counties of Colorado, 38 have retained their original county seat.
 * 3) Weld County has changed its county seat five times: in 1868, 1870, 1874, 1875, and 1877.
 * 4) Granite has served as the county seat of three counties: Lake County, Carbonate County, and Chaffee County.
 * 5) San Miguel (later Costilla) was designated the original county seat of Costilla County, Colorado Territory despite lying unbeknownst across the border in the Territory of New Mexico.