16 April, 2004 Denver, CO - Denver is the capital and the most populous city of Colorado, in the United States. Denver is a consolidated city-county located in the South Platte River Valley on the High Plains just east of the Front Range of the Southern Rocky Mountains. The Denver downtown district is located immediately east of the confluence of Cherry Creek with the South Platte River, approximately 15 miles (24 km) east of the foothills of the Rocky Mountains. Denver is nicknamed the Mile-High City because its official elevation is exactly one mile, or 5,280 feet (1,609 m) above sea level. The 105th meridian west of Greenwich passes through Denver Union Station, making it the reference point for the Mountain Time Zone. (Photo by Walter G. Arce/ASP, Inc.)