Whether you’ve been here for a couple months or your entire life, Arapahoe County residents realize that their community provides the best of everything Colorado has to offer. From babies to boomers and beyond, our residents put down roots, raise families, start and run businesses, and embrace the endless opportunities and amenities that make Colorado so unique.

Arapahoe County is one of Colorado’s fastest growing counties, with more than 650,000 residents. By 2030, about 800,000 are projected to live here, which would make us the most populous county in the metro area, surpassing the City and County of Denver. The County spans approximately 805 square miles and its diversity is evident throughout, from vibrant urban, suburban, and rural communities, to an unparalleled open space and trail system, to major employment centers and a robust multimodal transportation network. The County is also home to Centennial Airport, one of the busiest general aviation airports in the nation.

The County is home to 13 cities and towns, nine school districts and 450 local improvement and special service districts. It also has one of the lowest property tax mill levies in the state. Our County government only keeps 15 percent of the tax revenue it collects, to invest in County services and infrastructure; the rest goes to schools, cities and towns, and special districts like fire and water.

The Arapahoe County government serves its communities in ways both obvious and obscure. As the beating heart of local and regional government, we’re here for our neighbors on their best days—and their worst. County officials and employees share our residents’ goals of preserving our quality of life, whether urban, suburban or rural, on our roads or on our trails, at home or at work. By establishing practices that celebrate, protect and connect our many diverse assets, and by advocating fiscally responsible policies that are mindful of our history and anticipate our future, Arapahoe County strives to be the place we’re proud to call home.


The history of Arapahoe County is entwined with that of Colorado’s statehood. The County was named for the Arapaho Indians, who along with the Cheyenne Indians occupied most of Colorado when it was still a territory. Arapahoe County was originally part of the Territory of Kansas, and when Kansas became a state in 1861, Colorado was made a territory, with Arapahoe County as one of the 17 original counties stretching east to the Kansas border. Denver was the original County seat until 1902, when Arapahoe County was divided into five counties. The City of Littleton became the new County seat and remains so today.

County Structure 

Counties are one of America’s oldest forms of government, dating back to 1634, when the first county governments (shires) were established in Virginia. Arapahoe County is a constitutional subdivision of Colorado state government, which means the County can only exercise powers specifically expressed in statute or in the state constitution.

Arapahoe County acts through its Board of County Commissioners, which serves as the administrative and policy-making body for the County. The five-member board adopts ordinances in those limited areas for which specific authority has been given by the State Legislature, and it adopts resolutions to conduct all of its other business. 

The other constitutional officers elected to four-year terms are the Assessor, Clerk and Recorder, Coroner, Sheriff, and Treasurer. Constitutionally and statutorily, these elected offices are independent of one another and from the County Commissioners. Their powers and duties are prescribed by state statute. The County Commissioners have no direct authority over the other elected officials in the County, except that the Board approves budgets for all other elected officials’ departments.

Align Arapahoe: Performance Management

The County’s performance management program—Align Arapahoe—provides data-driven information to deliver results consistent with the County’s stated vision, mission, and values.

Demographic Profile

  • Population is 651,215. Only Denver and El Paso counties are larger.
  • 242,141 households. Since 2010, the population of persons 65 and over living alone in Arapahoe County has grown by 29 percent.
  • 36.9 years is the median age in the County. This is an increase of 1.2 years since 2010 
  • $76,768 is the median household income: $5,000 higher than that state-wide median income. 
  • 92.3 percent of Arapahoe County residents are high school graduates or higher. 
  • 42 percent have a bachelor's degree or higher: a 5 percent increase since 2010.
  • 40.7 percent bachelor’s degree or higher, percent of persons age 25+.
  • 254,250 housing units in the County, of which 63 percent are owner occupied. 

Learn more about the characteristics that distinguish Arapahoe County

Economic Profile

Arapahoe County is home to some of the nation's largest companies, representing the aerospace and defense, biosciences, broadband, construction, engineering, financial services, healthcare, hospitality, information technology and advanced manufacturing industries, among others. The County is also home to Centennial Airport, one of the 10 busiest general aviation airports in the nation.

The County’s workforce center–Arapahoe/Douglas Works!–serves as a critical resource for the region’s economic development activities, providing a variety of no-cost services to job seekers and businesses.

Arapahoe County is committed to ensuring a strong economic and business climate, supporting economic development efforts of our cities and towns by partnering with the following organizations to keep Arapahoe County strong: