Denver is the both the largest city and capital of the state of Colorado. It is the 3rd-most populous county in Colorado - El Paso County being the largest. Denver is often referred to as the Mile-High City because it is almost exactly mile above sea level (about 5,200 feet above sea level). It's height makes Denver one of the highest altitude big cities in the United States.

Denver has an estimated 2013 population of 680,000 residents. This makes the city the 19th-most populated city in the United States. The 2013 census notes that the 10-county Denver-Aurora Metropolitan area had an estimated population of 2.6 million people, making it rank as the 18th most populated metropolitan area in the United States of America. In the larger, 12-county Denver-Aurora-Boulder area the ranking is the 14th most populated area in the U.S., with a population of over 3.3 million people.