Denver (), officially the City and County of Denver, is the capital and most populous municipality of the U.S. state of Colorado. Denver is located in the South Platte River Valley on the western edge of the High Plains just east of the Front Range of the Rocky Mountains. With an estimated population of 727,211 in 2019, Denver is the 19th-most populous city in the United States, the fifth-most populous state capitol, and the most populous city located in the Mountain states. The metropolitan area surrounding Denver represents a majority of the population and economic activity in the Front Range region, an area within which an estimated 85% of Colorado's population lives. The Denver downtown district is immediately east of the confluence of Cherry Creek with the South Platte River, approxim