Arapahoe (KS) County, Colorado Genealogy

Arapahoe County, Kansas Territory was created 30 August 1855 within what are now Colorado borders. A probate judge was appointed, but the plan for holding court was left to his discretion. Arapahoe County was attached to Marshall County, Kansas for business purposes. The county was never organized, and a county seat was never established.

On 7 February 1859, the following daughter counties were created from parts of the old Arapahoe (1855) County, Kansas:


 * Arapahoe County, Kansas Territroy (east sides of modern Adams, Arapahoe, and Elbert, and parts of Washington, Lincoln, Crowley, Otero, Bent counties in Colorado)
 * Broderick County, Kansas Territory (modern Pueblo County, eastern Fremont and Custer, and southern El Paso counties, Colorado)
 * El Paso County, Kansas Territory (northwestern El Paso, southern Douglas and Teller counties, Colorado)
 * Fremont County, Kansas Territory (southern Park and Chaffee, Fremont, northern Custer and Saguache counties, Colorado)
 * Montana County, Kansas Territory (southern Boulder, Jefferson, Gilpin, Clear Creek, Denver, northern Douglas and Park, western quarters of Arapahoe and Adams counties, Colorado)
 * Oro County, Kansas Territory (central Adams, Arapahoe, and Elbert, and northwestern El Paso counties, Colorado)



When Colorado was organized 28 February 1861 its core included all parts of the original (Kansas) Arapahoe County. At that time three daughter counties were replaced, Broderick, Montana, and Oro, and their names were discontinued. The three other daughter counties, Arapahoe, El Paso, and Fremont, remained but with significantly modified borders.

At least part of these modern Colorado counties were in the original Kansas version of Arapahoe County: Adams, Arapahoe, Bent, Boulder, Chaffee, Cheyenne, Clear Creek, Crowley, Custer, Denver, Douglas, El Paso, Elbert, Gilpin, Fremont, Jefferson Kiowa, Kit Carson, Lake, Lincoln, Otero, Park, Pueblo, Saguache, Teller, and Washington counties.

For information about residents of Arapahoe County, Kansas Territory try searching records of:


 * Marshall County, Kansas
 * Kansas Historical Society
 * Arapahoe County, Colorado
 * Colorado State Archives
 * county records of the present-day Colorado county which now includes the former Arapahoe County land where the person lived 1859-1861.