Denver International Airport (DEN) is the largest airport in the United States by land area and a major connecting hub for transcontinental travel. Located northeast of Denver on the high plains of Colorado, it serves United Airlines as a primary hub and Southwest Airlines as one of its largest bases of operation, offering extensive domestic coverage and a growing roster of international routes.
Denver International Airport is distinguished by its iconic Jeppesen Terminal, whose white fiberglass tent roof — designed to evoke the snow-capped Rocky Mountains — is one of the most recognizable airport structures in the world. The airport spans approximately 53 square miles, making it the largest commercial airport in the United States by land area and one of the largest anywhere on earth.
DEN is organized around one main terminal (the Jeppesen Terminal) and three concourses: A, B, and C. An underground automated guideway train — sometimes called the Airport Train — connects the terminal to all three concourses at no cost to passengers. Concourse B is the largest and serves United Airlines exclusively. Concourse C is primarily used by Southwest Airlines. Concourse A handles a mix of domestic and international carriers.
The airport consistently ranks among the top five busiest in the United States by passenger traffic and sits at a high-altitude elevation of 5,431 feet above sea level — the highest of any major commercial airport in the country. Its position near the center of the continental United States makes it a natural connecting point for transcontinental routes.
Denver International Airport opened in February 1995, replacing Stapleton International Airport, which had served the city since 1929. The project was delayed multiple times and significantly exceeded its original budget, in part due to problems with an automated baggage handling system that became notorious in aviation history. When DEN finally opened, it immediately became one of the most modern large airports in the world.
The airport was designed with future growth in mind — its massive land footprint allowed for six runways at opening, with room to expand further. The Jeppesen Terminal takes its name from Elrey Borge Jeppesen, a pioneer in aviation navigation charting who was based in Denver. DEN is renowned not only for its architecture but also for its extensive public art collection, which includes large-scale murals and sculptures throughout the terminal and concourses.
Denver International Airport has one central passenger terminal — the Jeppesen Terminal — which houses ticketing, check-in, baggage claim, and ground transportation. From the terminal, passengers descend to an underground level and board the Airport Train to reach one of three concourses.
Concourse A handles a mix of carriers and is the primary concourse for international departures. It connects to the international arrivals facility and is the home of several international carriers including Lufthansa, British Airways, and Air Canada. Concourse B is United Airlines' domain and is the largest concourse at DEN, spanning more than a mile from end to end. Concourse C is primarily used by Southwest Airlines and other domestic carriers. All three concourses are accessible only via the underground train from the Jeppesen Terminal.
United Airlines is Denver's largest carrier and operates Concourse B as its primary hub facility. United provides extensive domestic connectivity from DEN and offers international flights to Europe, Mexico, and Canada. Southwest Airlines is the second-largest carrier and operates most of its DEN flights from Concourse C, with high-frequency service across its domestic network.
Other significant carriers at DEN include American Airlines, Delta Air Lines, Frontier Airlines (headquartered in Denver), Spirit Airlines, and Alaska Airlines. On the international side, Lufthansa, British Airways, Air Canada, and Icelandair operate transatlantic and transborder routes from Concourse A. DEN offers nonstop service to well over 200 destinations.
The Jeppesen Terminal and all three concourses feature a broad range of dining, retail, and passenger services. United Club lounges are located in Concourse B, and there are additional lounges including the Centurion Lounge (American Express) in Concourse C. Free Wi-Fi is available throughout the airport.
DEN is known for its extensive public art program, which features more than 40 permanent works throughout the terminal and concourses. The airport's underground train level includes large murals that are visible from the train itself. The terminal's mountain-view windows on the upper levels offer dramatic views of the Rocky Mountains on clear days. Nursing rooms, interfaith chapels, and pet relief areas are available throughout the airport.
Denver International Airport is connected to downtown Denver and the broader metro area by the RTD University of Colorado A Line commuter rail service, which runs directly from the Jeppesen Terminal to Denver Union Station in approximately 37 minutes. The A Line operates every 15 minutes during peak hours and provides connections to the broader RTD light rail and bus network.
The airport is accessible by highway via Peña Boulevard, which connects to I-70. Rideshare services operate from designated pickup zones on the lower level of the Jeppesen Terminal. Taxi service is available on the ground transportation level. Rental car companies are located in the Rental Car Center, accessible via a free shuttle from the terminal.
DEN offers a large on-site parking complex with several options including the Pikes Peak garage (closest to the terminal), the Mount Elbert garage, and multiple economy surface lots branded as Denali, Earle Hoyt, and other named lots. Parking rates vary by proximity and structure type, with economy lots offering the lowest rates and covered garage options available at a premium.
The RTD A Line to downtown Denver is a popular alternative to driving and parking, particularly for travelers from the city core. Parking reservations can be made in advance through the DEN website, which is recommended during peak periods such as ski season holidays and summer travel peaks.
Concourse B at DEN is exceptionally long — walking from one end to the other can take 15 minutes or more. Check your gate location before heading to Concourse B and allow extra time if your gate is at the far end. The underground train is free and runs frequently, making it the fastest way to move between the terminal and concourses.
DEN's elevation of more than a mile above sea level can affect some travelers, particularly those arriving from sea-level cities. Allow time to acclimate if you are continuing a journey by car into the mountains. During winter months, Denver's snowstorms can cause significant delays — check weather conditions before departure and consider travel insurance during peak winter travel. The A Line to Union Station is a fast and reliable option that avoids traffic on Peña Boulevard during busy periods.
Denver International Airport is a critical economic driver for the Denver metropolitan area and the state of Colorado. As a major hub connecting the Mountain West to both coasts and international markets, DEN enables Colorado's substantial tourism industry — including ski resorts, national parks, and outdoor recreation destinations — to attract visitors from across the country and around the world.
The airport supports hundreds of thousands of jobs in the Denver region and generates billions of dollars in annual economic output. DEN's function as United Airlines' primary hub gives Denver disproportionate air connectivity relative to its population, supporting the city's growing technology and energy sectors.
Denver International Airport is pursuing ongoing expansion to accommodate growing passenger demand. Planned projects include Concourse B expansion with additional gates, terminal improvements to the Jeppesen Terminal's Great Hall, and upgrades to ground transportation infrastructure. The airport has also undertaken sustainability programs targeting reduced carbon emissions, water conservation, and renewable energy usage consistent with Colorado's environmental goals.
DEN is a primary commercial airport and a major domestic hub. It functions as a high-capacity connecting airport for transcontinental travel and plays a key role in linking the western and central United States.
Airports within approximately 60 miles of Denver International Airport that may provide additional scheduled commercial, regional access.
Denver International Airport is a gateway to one of America's most dynamic regions — the Mountain West, Colorado's ski slopes, national parks, and the booming Front Range urban corridor. Its distinctive architecture, extensive route network, and direct rail connection to downtown Denver make it one of the more passenger-friendly large airports in the country. Understanding its concourse layout and the underground train system is the key to navigating DEN smoothly.
Take the RTD University of Colorado A Line commuter rail from the Jeppesen Terminal directly to Denver Union Station in Midtown Denver. The trip takes approximately 37 minutes and runs every 15 minutes during peak hours. It's the fastest and most predictable option, avoiding highway traffic on Peña Boulevard.
United Airlines is the largest carrier and operates from Concourse B. Southwest Airlines is the second-largest carrier and uses Concourse C. American Airlines, Delta, Frontier, Spirit, Alaska, and several international carriers also serve DEN.
The white tent-like roof of the Jeppesen Terminal is made of fiberglass-coated fabric supported by steel cables. The design was inspired by the snow-capped peaks of the Rocky Mountains, visible to the west of the airport on clear days. The roof structure also allows natural light into the terminal below.
All three concourses (A, B, and C) are accessed from the Jeppesen Terminal via a free underground automated train. You cannot walk between concourses directly — all inter-concourse travel must go through the train, which takes 1–3 minutes between stops.
For the most current flight schedules, parking availability, terminal maps, and ground transportation updates, visit the official Denver International Airport website.
Denver International Airport Official Site