Denver International Airport

Denver International Airport, locally known as DIA, is an international airport in the Western United States, primarily serving metropolitan Denver, Colorado, as well as the greater Front Range Urban Corridor. At 33,531 acres, it is the largest airport in the Western Hemisphere by land area and the second largest on Earth, behind King Fahd International Airport. Runway 16R/34L, with a length of 16000 ft, is the longest public use runway in North America and the seventh longest on Earth. The airport is 25 mi driving distance northeast of Downtown Denver, 19 mi farther than the former Stapleton International Airport which DEN replaced; the airport is actually closer to the City of Aurora than central Denver, and many airport-related services, such as hotels, are located in Aurora.

Opened in 1995, DEN currently serves 25 different airlines offering non-stop service to over 215 destinations throughout the Americas, Europe, and Asia; it was the fourth airport in the U.S. to exceed 200 destinations. The airport is a major hub for United Airlines and the largest operating base for both Frontier Airlines and Southwest Airlines. With over 40,000 employees, the airport is the largest employer in Colorado. The airport is located on the western edge of the Great Plains and within sight of the Front Range of the Rocky Mountains.

In both 2021 and 2022, DEN was the third busiest airport in the world as well as the third busiest airport in the United States by passenger traffic. In 2023, it was the sixth busiest airport in the world and remained the third busiest airport in the United States having served around 77.8 million passengers, more than a 12% increase from the prior year. DEN has been among the top 20 busiest airports in the world every year since 2000.

History
Denver has traditionally been home to one of the busier airports in the United States because its midcontinent location was ideal for an airline hub. Several airlines, notably United Airlines and Continental Airlines, were hubbed at the former Stapleton International Airport, helping make it the sixth-busiest airport in the country by the 1960s. But Stapleton was cramped, with little room to add additional flights and with runways too close together, leading to long waits in bad weather that would cause nationwide travel disruptions.

From 1980 to 1983, the Denver Regional Council of Governments investigated areas for a new area airport north and east of Denver. Meanwhile, in 1983, Federico Peña was elected mayor of Denver, campaigning on a plan to expand Stapleton onto Rocky Mountain Arsenal lands. The plan had broad support, but leaders in nearby Adams County threatened to sue over noise concerns.

Eventually Peña struck a deal: Adams County leaders would rally citizens to back a plan for Denver to annex 54 sqmi of the county to build an airport away from established neighborhoods. In 1988, Adams County voters approved the annexation. The proposal was met with some skepticism because of its location: 24 mi from the heart of the city. But seeing the importance of a Denver air hub to the national transportation system, the federal government put $500 million (equivalent to $ billion ) toward the new airport. The rest of the cost would be financed by bonds, to be repaid with fees on airlines. Ground was broken in September 1989.

Two years later, Mayor Wellington Webb inherited the megaproject, which at that time was scheduled to open on October 29, 1993. At the time United was refusing to move to the new airport over the high proposed fees. The airline finally relented under the condition that the airport include an automated baggage system.

Construction delays pushed opening day back, first to December 1993, then to March 1994. By September 1993, delays due to a millwright strike and other events meant opening day was pushed back again to May 1994.

In April 1994, the city invited reporters to observe the first test of the new automated baggage system. Reporters were treated to scenes of clothing and other personal effects scattered beneath the system's tracks and carts that would often toss the luggage right off the system. After the embarrassing preview, the mayor cancelled the planned May opening. The baggage system continued to be a maintenance hassle and was finally terminated in September 2005, with traditional baggage handlers manually handling cargo and passenger luggage.

DEN finally replaced Stapleton on February 28, 1995, 16 months behind schedule and at a cost of $4.8 billion (equivalent to $ billion ), nearly $2 billion over budget ($ billion ). The construction employed 11,000 workers. United Airlines Flight 1062 to Kansas City International Airport was the first to depart DEN and United Flight 1474 from Colorado Springs Airport was the first to arrive at the new airport.

[[File:Denver airport USGA 2002 mod.jpg|thumb|In 2002 when 16R/34L was under construction

]] In September 2003, runway 16R/34L was added, the airport's sixth and at 16000 ft, it is 4000 ft longer than the other runways. Its length, exceeded by only six other runways in the world, allows fully laden Airbus A380s and Boeing 747-8s to take off in the hot and high conditions at the airport, which is roughly 1 mi above sea level.

During a blizzard on March 17–19, 2003, the weight of heavy snow tore a hole in the terminal's white fabric roof, and over 2 ft of snow on paved areas closed the airport and its main access road (Peña Boulevard) for almost two days, stranding several thousand people. Another blizzard on December 20–21, 2006, dumped over 20 in of snow in about 24 hours. The airport was closed for more than 45 hours, stranding thousands. Following this, the airport invested heavily in new snow-removal equipment that has led to a dramatic reduction in runway occupancy times to clear snow, down from an average of 45 minutes in 2006 to just 15 minutes. In 2020, the airport was awarded the Balchen/Post award, which is presented by the Northeast Chapter of the American Association of Airport Executives (AAAE) for the outstanding snow and ice removal operation during difficult winter conditions.

After shunning DEN for over a decade for its high fees, Southwest Airlines entered the airport in January 2006 with 13 daily flights. Southwest has since rapidly expanded and is now the airport's second-largest carrier after United.

On November 19, 2015, a hotel was added to the airport and on April 22, 2016, DEN received commuter rail service to Denver Union Station with the opening of RTD's A Line.

On September 9, 2015, a political campaign was launched by Mayor Michael Hancock to radically expand commercial development at DEN, previously prohibited by intergovernmental agreement between Denver and Adams County. The changes to the agreement were approved by both Denver and Adams County voters in November 2015.

In 2018, work began on a major interior renovation and reconfiguration to the entire Jeppesen Terminal including the beginning phases of construction to relocate two out of the three TSA security checkpoints from the Great Hall on Level 5 to Level 6 (East & West) while simultaneously updating and consolidating airline ticket counters/check-in for all airlines. Eventually, both pre- and post-security gathering and leisure areas will be incorporated into the spaces where both expansive TSA security areas on Level 5 are currently located. The third TSA security checkpoint currently accessible via the Concourse A bridge is expected to be removed once the new Level 6 security areas are completed. The renovation and reconfiguration will bring back the original intent and use of the Great Hall as a large commons area for airport patrons and visitors to enjoy. First phases of completion—including updated check-in and baggage drop counters for United & Southwest Airlines as well as visual and facility updates to parts of the terminal—began in late 2020 and progressively continue to this day. In early February 2024, the first of two new security screening areas (West Security on Level 6) opened to the public. It is located directly north of the new United Airlines Check-In facilities. The new East Security, directly across the Great Hall from West, is expected to open in mid to late 2025. At that time both Level 5 North & South Security areas (who have been in operation for over 20 years) will be closed and removed in addition to the A-Bridge Security. This phased terminal project is expected to be completed by 2028.

Additionally in 2018, work commenced on a major gate expansion to all three concourses with 12 new gates being added to A (including several single and double-jetway gates with direct access to U.S. Customs and Border Protection), 11 to B, and 16 to C, for a total of 39 new gates. Following the completion of this project, United Airlines has leased 24 additional gates on both A and B (bringing its total gate count at DEN to around 90), as well as build a new United Club in A and expand their existing clubs in B. Southwest Airlines leased 16 of the new gates in C bringing its total gate count at DEN to 40, which is SWA's largest gate count at any single airport. As of November 2022, all new gates in A-West, B-West, B-East and C-East are in use and new retail and restaurant tenants will continue to open through 2024 as well as new art commissioned and installed through 2025. Additionally, all existing way-finding signs, flight information display systems and gate signs are expected to be replaced in the coming years matching what is found at the new gates and within the renovated portions of the terminal. When both the ongoing terminal and concourse projects are completed, the airport will be able to handle upwards of 100 million passengers per year.

In 2021, the airport experienced a notable failure of the train system. In response, a request for information from the private sector was issued to analyze options to possibly supplement the train system in the future. By 2023, several companies proposed their ideas to transport passengers.

In 2022, a committee was formed to support efforts to establish flights between Denver and Africa.

In August 2022, DEN broke ground on an additional gate expansion project that will bring a total of 14 ground loaded gates to the east end of Concourse A to be used solely for Frontier Airlines operations. This A-East wing is intended to be removed once a more permanent A-East expansion (similar to what just opened in A-West) occurs at an unknown future date. This will be a gain of four gates for Frontier once completed. Currently there are several ground loaded gates at this location which were constructed back in 2018 for United's temporary regional operations while a new and additional regional wing was being constructed onto the east end of Concourse B. The new United Concourse B regional wing opened in late 2022 and United has now vacated the A regional wing making way for Frontier to move in once the renovations and addition are completed. The expanded Concourse A wing for Frontier is expected to open by mid-2024.

In December 2023 DEN started construction on a new 'Center of Equity and Excellence in Aviation' which will help underserved communities and prepare current and future employees for a career in aviation. The CEEA will be located directly below the Westin Hotel and DEN Plaza and is expected to open in late 2024 or early 2025.

In late 2023, the airport laid out preliminary plans to add four new concourses with 100 more gates east and west of the terminal by 2045. The project is being referred to as 'Operation 2045' and will help support the airport’s goal of serving over 125 million passengers annually by that time.

Facilities


The airport is 23 mi from Downtown Denver, which is 15 mi farther away than Stapleton International Airport, the airport DIA replaced.

The 52.4 sqmi of land occupied by the airport is more than one and a half times the size of Manhattan (33.6 sqmi). DIA is larger in land area (excluding water) than the US cities of Boston, Massachusetts and San Francisco, California. DIA occupies the largest amount of commercial airport land area in North America, by a great extent. The land was transferred from Adams County to Denver after a 1989 vote, increasing the city's size by 50 percent and bifurcating the western portion of the neighboring county. All freeway traffic accessing the airport from central Denver leaves the city and passes through Aurora for nearly 2 mi, making the airport a practical exclave. Similarly, the A Line rail service connecting the airport with downtown Denver has two intervening stations in Aurora.

Terminal
DIA has one terminal, named The Jeppesen Terminal after aviation safety pioneer Elrey Borge Jeppesen, and three midfield concourses, spaced far apart. The three midfield concourses have a total of 179 gates in operation as of late 2022. Concourse A is accessible via a pedestrian bridge directly from the terminal building, as well as via the underground train system that services all three concourses. For access to Concourses B and C, passengers must utilize the train. All international arrivals without border pre-clearance are processed in Concourse A; this concourse also has 4 3-jetway international gates that can support ADG Group VI aircraft such as an Airbus A380 and a Boeing 747-8, the two largest commercial aircraft in the world.

In 2023, the airport announced a plan to significantly increase its passenger capacity by expanding the Jeppesen Terminal with additional check-in and TSA counters. The plan would also add new concourses with a further 100 gates.
 * Concourse A is used by Delta Air Lines, Frontier Airlines, JetBlue, United Airlines (including all international arrivals), and all international carriers. It has 60 gates, including several ground-level boarding and double jetway gates.
 * Concourse B is solely used for United Airlines flights. It has 72 gates, including four double jetways and several regional gates.
 * Concourse C is primarily used for Southwest Airlines flights, as well as American Airlines, Alaska Airlines, and most regional airliner flights. It has 47 gates, including four ground-level boarding gates.

Art and aesthetics


The Jeppesen Terminal's internationally recognized peaked roof, designed by Fentress Bradburn Architects, resembles snow-capped mountains and evokes the early history of Colorado when Native American teepees were located across the Great Plains. The catenary steel cable system, similar to the Brooklyn Bridge design, supports the fabric roof. DIA is also known for a pedestrian bridge connecting the terminal to Concourse A that allows travelers to walk from the main Terminal to Concourse A, while viewing planes taxiing beneath them. It offers views of the Rocky Mountains to the west and the high plains to the east.

Denver's public art program, which is financed by a mandatory 1% capital improvement budget, has resulted in a significant number of artworks being installed at the airport, where some can only be appreciated after passing through security. The artwork includes sculptures, murals, photos, sound art and paintings.

The airport features a bronze statue of Denver native Jack Swigert by Loveland, Colorado artist George Lundeen in Concourse B. Swigert flew on Apollo 13 as Command Module Pilot, and was elected to the House of Representatives in 1982, but died of cancer before he was sworn in. The statue is dressed in an A7L pressure suit, and is posed holding a gold-plated helmet. It is a duplicate of a statue placed at the United States Capitol in 1997. George Lundeen is also the sculptor of "The Aviator", a monumental bronze sculpture of Elrey Borge Jeppesen, for whom the terminal is named.

Denver International Airport has four murals by the Chicano artist Leo Tanguma. "Children of the World Dream of Peace" is in two-parts. The first depicts the horrors of war, with a man in a gas-mask brandishing a saber. The second, larger part shows this man toppled, and smiling children from many nations making swords into plowshares; Tanguma explains this is a reference to the Book of Isaiah 2:4: "and they shall beat their swords into plowshares—nation shall not lift up sword against nation, neither shall they learn war any more." Per Denver Public Art, "Children of the World Dream of Peace" is a powerful mural expressing the artist's desire to abolish violence in society. One section of the piece speaks to the tragedy and devastation of war and its impact on humanity. The mural then moves on to images of smiling children, dressed in traditional folk costumes from around the world, celebrating peace prevailing over war." "In Peace and Harmony With Nature" is also in two parts; Denver Public Art explains that "The first half of the mural shows children displaying great sadness over the destruction and extinction of life, as the second half of the artwork depicts humanity coming together to rehabilitate and celebrate nature." Tanguma confirms this was his intent.

In March 2019, the airport unveiled an animated, talking gargoyle in the middle of one of the concourses. The gargoyle interacted with passengers and joked about the supposed conspiracies connected to the airport.

Blue Mustang, by El Paso-born artist Luis Jiménez, was one of the earliest public art commissions for Denver International Airport in 1993. The 32 ft sculpture is a bright blue cast-fiberglass sculpture of a horse with glowing red eyes located between the inbound and outbound lanes of Peña Boulevard. Jiménez was killed in 2006 at age 65 while creating the sculpture when a part of it fell on him and severed an artery in his leg. At the time of his death, Jiménez had completed painting the head of the mustang. Blue Mustang was completed by others, and unveiled at the airport on February 11, 2008. The statue has been the subject of considerable controversy, and has acquired the nickname Blucifer for its demonic appearance.

Ground transportation
The Regional Transportation District (RTD) operates the A Line rail service between DIA and Denver Union Station in downtown Denver, making the 37 minute trip about every 15 minutes. RTD also operates an airport express bus service called skyRide between Arapahoe County or Boulder and DIA. There is also hourly service to Thornton on RTD route 104L, a limited stop bus. The airport is also served by two commuter routes with just a few runs per day: RTD route 145X to Brighton and 169L to Aurora.

Scheduled bus service is also available to points such as Fort Collins, and van services stretch into Nebraska, Wyoming, and Colorado summer and ski resort areas. Amtrak offers a Fly-Rail plan for ticketing with United Airlines for trips into scenic areas in the Western U.S. via a Denver stopover.

The airport is connected to the I-70 and Denver via the Peña Boulevard freeway. A number of car rental companies are located at the airport, providing courtesy shuttle services from Jeppesen Terminal Level 5, Island 4, to their parking areas.

The airport claims that it is completely accessible to bicycling travelers. The city of Denver's designated bike route consists of the non-separated shoulders of the 65-mph Peña Boulevard freeway, a route which Denver's former bicycle planner James Mackay has called "a facade, an appearance, a deceit, a contrivance." The airport suggests that cyclists who prefer a less-traveled route may use 56th Avenue to Valleyhead Road, a rural 55-mph highway with no shoulder.

Conspiracy theories
Conspiracies concerning the airport, inspired by the type of art, unusual architecture, and construction problems, started shortly after its completion. With the expansion of the internet, television shows such as Conspiracy Theory, and annual media reporting of these theories, they continued to grow. Airport administration decided to embrace the conspiracy theories instead of trying to fight them. In 2016, a small "Conspiracy Theories Uncovered" exhibition was installed in the terminal, explaining some of the more popular theories. In 2019, an animatronic gargoyle named Gregoriden, or Greg for short, that randomly makes statements such as "welcome to Illuminati headquarters" was installed. Some took offense to the gargoyle, claiming it was satanic, so the gargoyle was removed and replaced with a more muted version. Other gargoyle statues, sitting on open suitcases, are in the baggage claim area. Some also view these statues as malevolent, despite their intended purpose as playful artistic creations that are claimed to safeguard luggage.

In April 2019, the Roswell International Air Center and Denver International Airport became "supernatural sister airports." In the agreement, they would work together to enhance industry best practices that involve commerce, trade and tourism. It also includes a clause that they would share strategies for extraterrestrial combat. For the airport's 20th birthday, plans to decorate the airport property with crop circles proved to be too expensive, so they were not implemented. In a marketing campaign that was tied to renovations started in 2018, posters were created with aliens joking that breeding grounds for gargoyles or meeting halls for Freemasons were being constructed. The campaign was successful, generating over $8 million in revenue.

Theories

 * Tunnels: The delay in opening the airport and the large budget overrun led to a variety of rumors about the tunnels that were built under the airport. The scope has been exaggerated, and there is lore that the tunnels lead to underground survival bunkers for the rich and elite, military bases, homes for aliens, homes for lizard people, or to the North American Aerospace Defense Command. The actual use for the tunnels is to move luggage between check-in counters, airplanes and baggage claim areas. Employees have been known to prank the media by wearing lizard masks. Videos of blurry lizard people have appeared online and drawings of aliens have appeared on tunnel walls. However, other graffiti, besides alien drawings, exist along the tunnels.
 * New World Order and other secret societies: Because of the isolated location, there are rumors that the airport will be used by the New World Order as a prison or concentration camp. The time capsule at the airport showcases an inscribed plaque that has the Freemason symbol and the words "New World Airport Commission," which is a group that has never existed, prompting the conspiracy theory that the airport is controlled by Freemasons and linked to the New World Order or other secret societies. A spokesperson for the Denver International Airport, Alex Renteria, has said that the Freemasons had created the cover, and thus had included their symbol, but there is no evidence that they have any influence in running the airport. The wording about the commission was used to represent that the new airport would permit access to the world and is a reference to Dvorák's New World Symphony.
 * Nazism: Tanguma's murals have been purported to represent Nazism, death, or a prophecy of the end of the world, counter to the artist's meaning. The removal of the murals to keep them safe during construction prompted rumors that the project was an excuse to cover the truth. In addition, there are conspiracy theories around Nazism based on the supposedly swastika-shaped runway arrangement, which aerial views refute.
 * Alien languages: People have noted apparent markings that are supposed to represent alien or secret languages. The markings are actually Navajo language characters and identifiers for the airport artists.
 * Blue Mustang eyes: The red, glowing eyes have led some to call the horse statue demonic, thinking that the glowing eyes are referencing the Four Horsemen of the Apocalypse. The eyes are actually a tribute to the artist's father, who owned a neon light shop in Mexico.
 * Flat Earth: On TikTok in April 2023, a video went viral, claiming that an artistic 30-year-old world map art installation was new and confirmed flat earth theory.

Accidents and incidents

 * On February 16, 2007, 14 aircraft suffered windshield failures within a three-and-a-half-hour period at the airport. A total of 26 windshields on these aircraft failed. The NTSB opened an investigation, determining that foreign object damage was the cause, possibly the sharp sand used earlier that winter for traction purposes combined with wind gusts of 48 mi/h.
 * On December 20, 2008, a Continental Airlines Boeing 737-500 operating as Flight 1404 to Houston–Intercontinental Airport veered off the left side of runway 34R and caught fire during its takeoff roll at DIA. There were 38 injuries sustained by the passengers and crew; however, there were no fatalities. There was no snow or ice on the runway, however there were 31 knot crosswinds at the time of the accident. On July 13, 2010, the NTSB published that the probable cause of this accident was the captain's cessation of right rudder input, which was needed to maintain directional control of the airplane.
 * On April 3, 2012, an ExpressJet Embraer ERJ-145, registration N15973, operating as Flight UA/EV-5912 from Peoria, IL to Denver, was landing on 34R when the aircraft hit the approach lights and stopped on the runway. Smoke developed inside the aircraft and passengers were evacuated onto the runway. One passenger was taken to a hospital for treatment of his injuries.
 * On February 20, 2021, United Airlines Flight 328, a Boeing 777-200 that was on its way from Denver to Honolulu, Hawaii, suffered engine damage just after takeoff and had to return to Denver International Airport. Debris from the damaged engine fell on a neighborhood in Broomfield, a city around 25 miles from the airport. The damaged airplane landed safely on runway 26 and no injuries were reported.
 * On April 7, 2024, Southwest Airlines Flight 3695, a Boeing 737-800 bound for Houston, Texas, suffered a detached engine cowling which struck a wing flap during take-off. The plane returned to Denver, where it landed safely. The incident was recorded by a passenger and put on online media. There were no injuries reported to passengers or crew.