Castle Pines is a statutory city located in the U.S. state of Colorado. It is within Douglas County in the Town of Castle Rock to the north and City of Lone Tree to the south. It has a total area of 9.57 square miles at 39°27′45″N 104°52′14″W. The elevation is 6,368 feet above sea level. Castle Pines was incorporated on November 6, 2007. As of the 2010 census data, it had a total population of 10,360. The population density was 1,074.38/sq mi. It has Zip code 80108.