The Town of Parker is a Home Rule Municipality in Douglas County, Colorado, United States. As a self-declared “Town” under the Home Rule Statutes, Parker is the second most populous town in the county; Castle Rock is the most populous. In recent years, Parker has become a commuter town at the south eastern most corner of the Denver Metropolitan Area. As of the 2010 census, the town population was 45,297, over 145 times the population of 285 when Parker incorporated in 1981. Parker is now the 19th most populous municipality in the State of Colorado.

The City of Centennial is a Home Rule City located in Arapahoe County, Colorado, United States, and part of the Denver-Aurora metropolitan area. The city had a total population of 100,377 in 2010 census.  Centennial is the tenth-most populous municipality in the state of Colorado and its 2001 incorporation was the largest in U.S. history. Centennial is ranked as the 15th safest[5] city in the country.

Castlewood is a former census-designated place (CDP) in southern Arapahoe County, Colorado, United States. The population was 25,567 at the 2000 census.  It has been a part of the city of Centennial since the city’s incorporation in 2001.

Southglenn is a former census-designated place (CDP) in Arapahoe County, Colorado, United States. The population was 43,520 at the 2000 census.  It has been a part of the city of Centennial since the city’s incorporation in 2001.

The Town of Castle Rock is the county seat of Douglas County, Colorado, United States[5] and is named after the prominent castle tower-shaped butte near the center of town. It is part of Colorado’s Front Range Urban Corridor and is located roughly 28 miles (45 km) south of Denver and 37 mi (60 km) north of Colorado Springs. As of the 2010 census, the town had a population of 48,231.