Denver (officially, The City and County of Denver) (/ˈdɛnvər/; Arapaho: Niinéniiniicíihéhe') is the capital and most populous municipality of the U.S. state of Colorado. As of 2014, Denver is also the most populous county in 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. The Denver downtown district is located immediately east of the confluence of Cherry Creek with the South Platte River, approximately 12 mi (19 km) east of the foothills of the Rocky Mountains. Denver is nicknamed the Mile-High City because its official elevation is exactly one mile (5,280 ft or 1,610 m) above sea level, making it one of the highest major cities in the United States.