It ranks among the top 10 busiest airports in the United States and is the largest airport in area in the country. It is a major hub for United Airlines and the operations base of United's low-cost subsidiary Ted. Frontier Airlines, one of the fastest growing discount airlines in the US also uses DIA as their main hub. The airport uses DEN as is its IATA airport code and KDEN as its ICAO airport code.
DIA replaced the old Stapleton International Airport in 1995, making it one of the youngest major airports in the US. It was built by the initiative of Denver mayor Federico Peña, but its construction ran into many problems.
Nowadays, the main complaint about the airport is its distant location from the city center, necessary to accommodate the airport's vast size (137km²). The airport also charges high landing fees to airlines in order to offset its hefty construction costs. Tickets to and from Denver are very expensive, lessening its appeal as a cross-country hub.
DIA has three midfield concourses. They are spaced far apart, and if the inter-terminal people mover system breaks down, it becomes difficult for passengers to board their flights on time, which has only happened once since the airport has been opened. The basic layout is very similar to Atlanta's airport, except that departures and arrivals are on different levels of the terminals.
During a major blizzard in 2003, the heavy snow tore a hole in the one of the terminal's characteristic white fabric roofs, which were designed to be reminiscent of the snow-capped Rocky Mountains in winter.
The airport covers some 60 or 70-square miles or so and is the largest airport in the country. It is so large that it is larger than Chicago O’Hare, Dallas Forth Worth and Atlanta/Hartsfield combined. The current facility was built to replace the aged Denver Stapleton Airport in 1995 or so that was much closer to the city center.
The central terminal is known for its white, fabric roof reminiscent of the white-capped Rocky Mountains or the “teepees” of the Native Americans who inhabited the area, depending on who you ask. Being inside makes you feel as though you are in a giant tent. The clean and spacious central terminal has the TSA screening booths, numerous car rental agencies, restaurants and the enormous baggage claim on the bottom level. The airport’s layout is similar to Atlanta’s. There are 3 concourses separated by some three-quarters of a mile or so and connected by an underground train. Frontier Airlines is closest to the main terminal while United is further out at Concourse 3.
DIA is the 2nd largest hub for United Airlines and is the only hub for smaller, classier and low-cast carrier, Frontier Airlines.