The U.S. state of Colorado has twenty-one statistical areas that have been delineated by the Office of Management and Budget (OMB). Statistical areas are important geographic delineations of population clusters used by the OMB, the United States Census Bureau, planning organizations, and federal, state, and local government entities. On March 6, 2020, the OMB delineated four combined statistical areas, seven metropolitan statistical areas, and ten micropolitan statistical areas in Colorado (map pictured). The most populous of these statistical areas is the Denver–Aurora, CO Combined Statistical Area, with a population of 3,623,560 at the 2020 census. (Full list...)