Denver and Aurora are the main cities of the Denver-Aurora-Broomfield , CO Metropolitan Statistical Area , a United States metropolitan area ( MSA ) . In 2007 , the cities within the statistical area had about 2,464,866 people , which makes it the MSA with the 22nd most people . Denver and Aurora are the principal cities of the Denver-Aurora-Broomfield , CO Metropolitan Statistical Area , which in 2007 had an estimated population of 2,464,866 .