Arapahoe County History
In 1861, when Kansas was made a state, Colorado was made a territory with Arapahoe County as one of the 17 original counties. The original Arapahoe County was 30 miles wide and extended from Sheridan Boulevard, the present western boundary of Denver, Adams and Arapahoe counties to the Kansas border. This peculiar shape was due to the practice of giving counties with large amounts of plains territory at least some of the foothill territory where there was water for mining and irrigation. Even though Arapahoe County did not reach the foothills, the streams running from the mountains supplied water.
As settlers came in and took up lands on the eastern portions of the state, new counties were created and cut down to their present size. In the late 1820’s, trappers searched this region for beavers to supply the great demand for men’s beaver hats. In the late 1830’s and 1840’s, the demand shifted to buffalo skins. In 1832, the first trading post on the South Platte River was built on Cherry Creek, which was then part of Arapahoe County.
In 1848, gold prospectors on their way to California stopped in Colorado long enough to pan its streams. They found gold on West Dartmouth Avenue, just west of Englewood where Dry Creek flows into the Platte River. This was the first important discovery of gold in Colorado and was called Placer Camp or The Mexican Diggings. The Russell party found more gold down the river where it joined Cherry Creek. Here, they established a camp later called Denver. Denver became the seat of Arapahoe County, remaining so until 1902, when the County was divided into several counties that make up the Denver metro area today. Other discoveries were made.
Today, Arapahoe County is a land of contrast. The County spans 806 square miles, has a population of more than 530,000 and is one of Denver’s fastest growing neighbors. While three-fourths of the County is rural, the western part of the County is largely urban with wonderful communities that have accommodated the influx of latter day settlers. Industrial growth included the Martin Marietta plant. The Denver Technological Center, Centennial Airport and Greenwood Plaza are huge complexes, which house offices of world famous corporations. The eastern end of the county remains largely rural with wheat farms and a few cattle and sheep ranches.
Arapahoe County was named for the Arapaho Indians, one of the larger tribes of plains Indians, who along with the Cheyenne occupied Arapahoe County east of the foothills running into what is now western Kansas.
Arapahoe County is Colorado’s first county, since almost half of the entire area now Colorado was Arapahoe County of the Kansas territory.
Arapahoe County is one of the 64 counties in the U.S. state of Colorado. As of the 2010 census, the population was 572,003, making it the third-most populous county in Colorado. The county seat is Littleton, and the most populous city is Aurora.
County Seat: Littleton
Area: 805 mi²
Founded: 1861
Population: 607,070 (2013)