Denver International Airport ( IATA: DEN, ICAO: KDEN, FAA LID: DEN), often referred to as DIA, is an airport in Denver, Colorado. By land size, at 53 square miles (140 km 2), it is the largest international airport in the United States, and the third largest international airport in the world after King Fahd International Airport and Montréal-Mirabel International Airport. Runway 16R/34L is the longest public use runway in the United States. In 2009, Denver International Airport was the tenth-busiest airport in the world by passenger traffic with 50,167,485 passengers. It was also the fifth-busiest airport in the world by aircraft movements with 606,006 movements. The airport is located in northeastern Denver, Colorado, and is operated by the City and County of Denver. Denver International Airport is the busiest and largest airport in the United States without non-stop service to and from Asia, although the airport is actively seeking such flights. DIA was voted Best Airport in North America by readers of Business Traveler Magazine five years in a row (2005”“2009) and was named "America's Best Run Airport" by Time in 2002. Denver International Airport is the main hub for low-cost carrier Frontier Airlines and commuter carrier Great Lakes Airlines. It is also the second-largest hub for United Airlines (after Chicago's O'Hare International Airport). Following United's merger with Continental Airlines, the airport will be the fourth largest hub for United after Houston, Chicago, and Newark respectively. The airport is also a focus city for Southwest Airlines. Since commencing service to Denver in January 2006, Southwest has added over 40 destinations, making Denver its fastest-growing market. Denver International Airport is the only airport in the United States to have designed and implemented an ISO 14001-certified environmental management system that covers the entire airport.

Features

Aesthetics
The airport's distinctive white tensile fiberglass roof is aesthetically designed to be reminiscent of the snow-capped Rocky Mountains in winter. The catenary steel cable system, similar to the Brooklyn Bridge design, supports the roof. DIA is also known for a pedestrian bridge connecting the terminal to Concourse A that allows travelers to view planes taxiing directly underneath and provides sweeping views of the Rocky Mountains to the West and the high plains to the East.

Art
Both during construction and after the opening of the airport, Denver International Airport has set aside a portion of its construction and operation budgets for art. Gargoyles hiding in suitcases are present above the exit doors from baggage claim. The corridor from the Jeppesen Terminal and Concourse A usually contains additional temporary exhibits. Finally a number of different public art works are present in the underground train that links the main terminal with the concourses. Mustang, by New Mexico artist Luis Jiménez, was one of the earliest public art commissions for Denver International Airport in 1993. Standing at 32 feet (9.8 m) tall and weighing 9,000 pounds (4,100 kg), "Mustang" is a blue cast-fiberglass sculpture with red shining eyes located between the inbound and outbound lanes of Peña Boulevard. Jiménez died in 2006 while creating the sculpture when the head 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. The sculpture was completed with the help of the artist's staff, family, and professional race-car painters, Camillo Nuñez and Richard LaVato. Upon completion, the sculpture was sent to California for assembly and then shipped to Denver. "Mustang" was unveiled at DEN on February 11, 2008. "Mustang" has received a mixed review from Colorado citizens. Many critics of the sculpture are attempting to have it removed, however the city plans to leave the installation in place for 5 years before making any decisions regarding its future. The controversy over the sculpture has received a great deal of media attention as well with coverage from the local news outlets to The Wall Street Journal, CNN, and The Daily Show.

Automated baggage system
The airport's computerized baggage system, which was supposed to reduce flight delays, shorten waiting times at luggage carousels, and save airlines in labor costs, turned into an unmitigated failure. An airport opening originally scheduled for October 31, 1993, with a single system for all three concourses turned into a February 28, 1995, opening with separate systems for each concourse, with varying degrees of automation. The system's $186 million original construction costs grew by $1 million per day during months of modifications and repairs. Incoming flights on the airport's B Concourse made very limited use of the system, and only United, DIA's dominant airline, used it for outgoing flights. The 40-year-old company responsible for the design of the automated system, BAE Automated Systems of Carrollton, Texas, at one time responsible for 90% of the baggage systems in the United States, was acquired in 2002 by G&T Conveyor Company, Inc. The automated baggage system never worked as designed, and in August 2005, it became public knowledge that United would abandon the system, a decision that would save them $1 million per month in maintenance costs.

Solar energy system
Between February and August 2008, construction of an on-site, two- megawatt solar energy system took place. The single-axis tracking system provides 3.5 million kilowatt-hours of energy per year and uses 9,200 solar panels made by Sharp. Originally designed to power a jail, it spares the environment of more than five million pounds of carbon emissions annually. The system generates the equivalent of half the energy needs of the underground trains that move people between concourses. The $13 million-plus system sits on 7.5 acres (or 30,000 m 2), clearly visible to people entering and exiting the airport. WorldWater & Solar Technologies Corp. designed and built the system, while MMA Renewable Ventures LLC"rather than DIA"owns the solar farm and sells its energy to the airport.

Telecommunications
DIA has public Wi-Fi access available throughout the airport. The free service is ad-supported through an advertising-filled HTML frame that is inserted into the top of the browser window. Users of the Wi-Fi network are also required to view a 30-second advertising video in the browser before Internet access is granted, although in many cases a click-through button is provided to avoid viewing the ad. The network is managed by FreeFi Networks, a Los Angeles-based firm. T-Mobile HotSpot service is available in the airport lounges run by United Airlines, American Airlines, and Delta Air Lines. The airport has pay-per-use kiosks which can be used to access the Internet and to play video games. The current stations were developed by Zoox Stations and were installed in 2007.

Geography
The airport is 25 miles (40 km) from downtown Denver, which is 19 miles (31 km) farther away than Stapleton International Airport, the airport it replaced. The distant location was chosen to avoid noise impacts to developed areas, to accommodate a generous runway layout that would not be compromised by winter storms, and to allow for future expansion. The 33,457 acres (52.277 sq mi; 135.40 km 2) of land occupied by the airport is nearly twice the land area of Manhattan. The land was transferred from Adams County to Denver after a 1989 vote, increasing the city's size by 50 percent. However, much of the city of Aurora is actually closer to the airport than the developed portions of Denver, and all freeway traffic accessing the airport from central Denver passes through Aurora. Airport officials say its large area contributes to it having the highest number of wildlife strikes in the United States (2,090 this decade ”“ although it ranked seventh on basis of takeoffs and landings).

History
In September 1989, under the leadership of Denver Mayor Federico Peña (after whom Peña Boulevard is named), federal officials authorized the outlay of the first $60 million for the construction of DIA. Two years later, Mayor Wellington Webb inherited the megaproject, scheduled to open on October 29, 1993. Delays caused by poor planning and repeated design changes due to changing requirements from United Airlines caused Mayor Webb to push 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 15, 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, while the actuators that moved luggage from belt to belt would often toss the luggage right off the system instead. The mayor cancelled the planned May 15 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. On September 25, 1994, the airport hosted a fly-in that drew several hundred general aviation aircraft, providing pilots with a unique opportunity to operate in and out of the new airport, and to wander around on foot looking at the ground-side facilities"including the baggage system, which was still under testing. FAA controllers also took advantage of the event to test procedures, and to check for holes in radio coverage as planes taxied around and among the buildings. DIA finally replaced Stapleton on February 28, 1995, 16 months behind schedule and at a cost of $4.8 billion, nearly $2 billion over budget. The construction employed 11,000 workers. United flight 1062 to Kansas City International Airport was the first to depart and United flight 1474 from Colorado Springs Airport was the first to arrive. After the airport's runways were completed but before it opened, the airport used the codes ( IATA: DVX, ICAO: KDVX). DIA later took over ( IATA: DEN, ICAO: KDEN) as its codes from Stapleton when the latter airport closed. During the blizzard of March 17”“19, 2003, heavy snow tore a hole in the terminal's white fabric roof. Over two feet of snow on the paved areas closed the airport (and its main access road, Peña Boulevard) for almost two days. Several thousand people were stranded at DIA. In 2004, DIA was ranked first in major airports for on-time arrivals according to the FAA. Another blizzard on December 20 and 21st, 2006 dumped over 20 inches (51 cm) of snow in about 24 hours. The airport was closed for more than 45 hours, stranding thousands.

Design and expandability
Denver has traditionally been home to one of the busier airports in the nation because of its location. Many airlines including United Airlines, Continental Airlines, Western Airlines, TWA, the old Frontier Airlines and People Express were hubbed in Denver and there was also a significant Southwest Airlines operation at the old Stapleton International Airport. At times, Denver was a hub for three or four airlines. Gate space was severely limited at Stapleton, and the runways at the old Stapleton were unable to deal efficiently with Denver's weather and wind patterns, causing nationwide travel disruption. These problems were the main justification for the new airport. The project began with Perez Architects and was completed by Fentress Bradburn Architects of Denver. The signature DIA profile, suggestive of the snow capped Rocky Mountains, was first hand sketched by Design Director Curtis W. Fentress. Seized upon by then Mayor, Federico Peña, as the iconic form he was looking for ”“ "similar to the Sydney Opera House" ”“ DIA's design as well as its user-optimized curbside to airside navigation has won DIA global acclaim and propelled its designer, Fentress, to one of the foremost airport designers in the world. Fentress Architects is currently at work on the modernization of LAX. With the construction of DIA, Denver was determined to build an airport that could be easily expanded over the next 50 years to eliminate many of the problems that had plagued Stapleton International Airport. This was achieved by designing an easily expandable midfield terminal and concourses, creating one of the most efficient airfields in the world. At 33,457 acres (13,540 ha), DIA is by far the largest land area commercial airport in the United States. Dallas/Fort Worth International Airport is a distant second at 18,100 acres (7,325 ha). The 327-foot (100 m) control tower is one of the tallest in North America. The airfield is arranged in a pinwheel formation around the midfield terminal and concourses. This layout allows independent flow of aircraft to and from each runway without any queuing or overlap with other runways. Additional runways can be added as needed, up to a maximum of 12 runways. Denver currently has four north/south runways (35/17 Left and Right; 34/16 Left and Right) and two east/west runways (7/25 and 8/26). DIA's sixth runway (16R/34L) is the longest commercial precision-instrument runway in North America with a length of 16,000 feet (4,877 m). Compared to other DIA runways, the extra 4,000-foot (1,200 m) length allows fully loaded jumbo jets to take off in Denver's mile-high altitude during summer months, thereby providing unrestricted global access for any airline using DIA. The sixth runway can also accommodate the Airbus A380. The midfield concourses allow passengers to be screened in a central location efficiently and then transported via a rail system to three different passenger concourses. Unlike Hartsfield-Jackson Atlanta International Airport upon which the midfield design was based, Concourses B and C are not connected by any kind of walkway; they are only accessible via train. The taxiways at Denver have been positioned so that each of the midfield concourses can expand significantly before reaching the taxiways. B Concourse, which is primarily used by United Airlines, is longer than the other two concourses, but all three concourses can be expanded as needed. Once this expansion is exhausted, space has been reserved for Concourses D and E. All international flights requiring customs and immigration services currently fly into Concourse A. Currently eight gates are used for international flights. These north facing gates on Concourse A are equipped to divert incoming passengers to a hallway which connects to the upper level of the air bridge, and enters Customs and Immigration in the north side of the Jeppesen Terminal. These gates could also be easily modified to allow boarding on both the upper deck and the lower deck of larger planes such as the Airbus A380. As part of the original design of the airport the city specified passenger volume "triggers" that would lead to a redevelopment of the master plan and possible new construction to make sure the airport is able to meet Denver's needs. The city hit its first-phase capacity threshold in 2008, and DIA is currently revising the master plan. As part of the master plan update, the airport announced selection of Parson's transportation group to design a new hotel, rail station and two bridges leading into the main terminal. Santiago Calatrava has been selected as the architect for the project. In addition, before hitting the 60 million passenger volume trigger, the airport is planning on constructing an additional runway, 20+ new gates on the existing concourses, two additional International Gates as well as improvements to the baggage system and passenger train. Once fully built out, DIA should be able to handle 110 million passengers per year, up from 32 million at its opening.

Terminal and concourses

Jeppesen Terminal
Jeppesen Terminal, named after aviation safety pioneer Elrey Jeppesen, is the land side of the airport. Road traffic accesses the airport directly off of Peña Boulevard, which in turn is fed by Interstate 70 and E-470. Two covered and uncovered parking areas are directly attached to the terminal ”“ three garages and an economy parking lot on the east side; and four garages and an economy lot on the west side. The terminal is separated into west and east terminals for passenger drop off and pickup. Linked below is a map of the airlines associated with the terminals. The central area of the airport houses two security screening areas and exits from the underground train system. The north side of the Jeppesen Terminal contains a third security screening area and a segregated immigration and customs area. A large fountain is currently being removed due to the expansion project currently underway. Passengers are routed first to airline ticket counters or kiosks for checking in. Since all gates at Denver are in the outlying concourses, passengers must pass through any one of the three separate security screening areas for admittance into the secure air side of the airport (one at each end of the main terminal, with escalators down to the trains, plus one at the end of the walkway to Concourse A). After leaving the main terminal via the train or pedestrian bridge, passengers can access 95 full-service gates on 3 separate concourses (A, B, & C), plus gates for regional flights. Stone used in the terminal walls was supplied by the Yule Marble Quarry, also used for the Tomb of the Unknown Soldier and the Lincoln Memorial. South Terminal Redevelopment Program A new $600 million adjunct terminal next to the Jeppesen terminal will house a railway station, a 500-room hotel and conference center that will be completed on 2016. The rail link will provide a direct linkage between downtown Denver and the airport.

Concourses
Denver International Airport has three midfield concourses, spaced far apart. 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 Denver International Airport Automated Guideway Transit System. On one occasion in the late 1990s, the train system encountered technical problems and shut down for several hours, creating a tremendous back-log of passengers in the Jeppesen Terminal since no pedestrian walkways exist between the terminal and the B and C Concourses. Since that day the airport's train system has continued to operate without any further major service interruption. The concourses and main terminal have a similar layout to Atlanta's airport, except that Denver has no T gates directly attached to the terminal and the space between terminals at DIA is much wider than the space between the terminals in Atlanta. This allows for maximum operating efficiency as aircraft can be pushed away from their gate awaiting departure and other arriving and departing aircraft can still taxi through the alley behind them without delay. The airport collects landing fees, rent and other revenues from the airlines to help offset its operating costs. Denver International Airport is owned and operated by the City and County of Denver, but does not operate using tax dollars. Instead, the airport is an "enterprise fund" generating its own revenues in order to cover operating expenses. The airport operates off of revenue generated by the airlines ”“ landing fees, rents and other payments ”“ and revenues generated by non-airline resources ”“ parking, concessions revenues, rent and other payments. On December 14, 2006, The Denver Post reported that DIA is in the design phase of expanding Concourse C in the airport's "first major concourse expansion." At least eight new gates are planned for construction at the east end of Concourse C and the project has an estimated pricetag of approximately $160 million. If the project is given the green light to move past the design phase, construction on Concourse C is estimated to take 3 years and will allow primarily Southwest Airlines, but also other carriers, to increase flight schedules at one of the nation's fastest-growing airports. Concourse B also recently expanded with the addition of a regional jet terminal at the east side of Concourse B. This Regional Jet concourse consists of two smaller concourses or fingers which are connected to Concourse B via two bridges. These gates allow direct jet bridge access to smaller Regional Jets. With the opening of the Regional Jet Concourse, United Airlines has left Concourse A entirely and now operates solely from Concourse B, with the exception of international flights requiring customs support. The Airport has also announced plans to revise the Airport Master Plan to account for changing circumstances since the airport opened. According to the December 14, 2006, Denver Post and Rocky Mountain News articles, plans being drafted could possibly include an extension of the Main terminal to the South. This change would increase the number of ticketing counters and would also include a rail station for the terminus of the FasTracks commuter rail line from Denver's Union Station. Concourse A Note: Concourse A handles all international arrivals at Denver (excluding airports with border preclearance) as well as certain departing flights: Concourse A has 37 Gates: A24”“A68 with four international boarding gates, gate A37 is used by British Airways and gates A41 & A43 are used by Aeromexico, Air Canada and Lufthansa. Denver is one of the busiest airports worldwide with only limited international operations. Frontier Airlines is the main carrier in Concourse A. American Airlines' Admiral's Club is located in Concourse A. Concourse B Concourse B has 77 Gates: B15”“B29, B31”“B33, B35”“B39, B42”“B95 In November 2009, United and DIA reached an agreement in which United released five of its gates in the western end of the concourse. DIA in return leased these gates to United's Star Alliance partners US Airways and Continental Airlines. United Airlines has two Red Carpet Clubs on Concourse B, both one level above the main area of the concourse. One is adjacent to gate B32, and the other is adjacent to gate B44. Concourse C Concourse C has 22 Gates: C28”“C49 Southwest and Delta are the main carriers in Concourse C. Concourses D and E The airport has reserved room for two more Concourses to be built beyond Concourse C for future expandability. Concourse D can be built without having to move any existing structure. The underground train system, however, will have to be extended. Concourse E will require moving a United Airlines hangar. However, before construction on Concourses D and E begins, Concourses A, B, and C can be extended in both directions to contain 99 gates per concourse. This is evident from the fact that the gate number 40 was selected to be the median gate number at the middle of each concourse; theoretically, this allows for gates 1 through 40 to be located to the west, and gates 41 to 99 to be located to the east, of the passenger train system. Signs as one enters the mezzanine level indicate a separation of 1-40 on one side and 41-99 on the other.

Airlines and destinations
Denver International Airport is the largest hub of Frontier Airlines and the second-largest hub for United Airlines. Southwest Airlines continues to grow rapidly at the airport even after a failed bid to buy rival Frontier Airlines. Denver is the point to point carrier's seventh largest city. The airport is also the main hub of Great Lakes Airlines. DIA was a hub for the now defunct Western Pacific Airlines and is also a growing focus city for Southwest Airlines. The three largest airlines serving DIA are United Airlines, Southwest, and Frontier Airlines, controlling about 42.3%, 21.4%, and 20.9% of all passenger traffic at DEN in December 2010, respectively. United and Frontier serve destinations in Canada, Costa Rica, and Mexico while foreign flag carriers Aeroméxico, Air Canada, British Airways and Lufthansa operate flights to their hubs. An Alexander Eaglerock biplane at Concourse B's west end Overhead view of the Concourse C train station

Top Destinations

Airlines Destinations Concourse Aeroméxico Seasonal: Mexico City A Air Canada Montréal-Trudeau, Toronto-Pearson A AirTran Airways Atlanta, Milwaukee A Alaska Airlines Seattle/Tacoma Seasonal: Anchorage A American Airlines Chicago-O'Hare, Dallas/Fort Worth, Miami A American Eagle Chicago-O'Hare, Los Angeles A British Airways London-Heathrow A Continental Airlines Chicago-O'Hare , Cleveland, Fort Lauderdale , Houston-Intercontinental, Las Vegas, Newark Seasonal: Anchorage B Delta Air Lines Atlanta, Cincinnati/Northern Kentucky, Detroit, Minneapolis/St. Paul, New York-JFK C Delta Connection operated by Atlantic Southeast Airlines Memphis C Delta Connection operated by Comair Cincinnati/Northern Kentucky C Delta Connection operated by Mesaba Airlines Memphis C Delta Connection operated by SkyWest Airlines Salt Lake City C Frontier Airlines Akron/Canton, Atlanta, Austin, Cancún, Chicago-Midway, Dallas/Fort Worth, Dayton, Detroit, Fort Lauderdale, Fort Myers, Houston-Hobby, Indianapolis, Kansas City, Knoxville (TN) , Las Vegas, Liberia (CR), Long Beach, Los Angeles, Louisville, Madison, Milwaukee, Minneapolis/St. Paul, Nashville, New Orleans, New York-LaGuardia, Newport News/Williamsburg, Orange County, Orlando, Philadelphia, Phoenix, Portland (OR), Puerto Vallarta, Sacramento, St. Louis, Salt Lake City, San Diego, San Francisco, San José del Cabo, Seattle/Tacoma, Spokane, Tampa, Tucson, Washington-National Seasonal: Anchorage, Boise, Cozumel, Fairbanks, Jackson Hole, Mazatlán, San José de Costa Rica A Frontier Airlines operated by Lynx Aviation Aspen, Colorado Springs, Durango A Frontier Airlines operated by Republic Airlines Albuquerque, Aspen, Billings, Branson (MO), Bozeman, Colorado Springs, Dallas/Fort Worth, Des Moines, Durango, Grand Rapids, Kansas City, Long Beach, Los Angeles, Milwaukee, Minneapolis/St. Paul, Oklahoma City, Omaha, Phoenix, Provo (UT) , Salt Lake City, San Antonio, San Diego, Santa Barbara, Sioux Falls , Wichita Seasonal: Green Bay, Hayden/Steamboat Springs, Ixtapa/Zihuatanejo A Great Lakes Airlines Alamosa, Alliance, Billings, Chadron, Cheyenne, Cortez, Dickinson, Dodge City, Ely, Farmington, Garden City, Gillette, Glendive, Glasgow (MT), Grand Island, Great Bend, Havre, Hays, Huron, Kearney, Laramie, Lewistown, Liberal, McCook, Miles City, Moab, North Platte, Page, Pierre, Prescott, Pueblo, Riverton, Rock Springs, Scottsbluff, Sheridan, Sidney, Telluride, Vernal, Williston, Wolf Point, Worland A JetBlue Airways Boston, New York-JFK A Lufthansa Frankfurt A Southwest Airlines Albuquerque, Amarillo, Austin, Baltimore, Boise, Boston, Burbank , Chicago-Midway, Columbus (OH) , Detroit, El Paso, Fort Lauderdale, Hartford, Houston-Hobby, Indianapolis, Jacksonville , Kansas City, Las Vegas, Los Angeles, Minneapolis/St. Paul, Nashville, New Orleans, Newark , Oakland, Oklahoma City, Omaha, Ontario, Orange County, Orlando, Philadelphia, Phoenix, Pittsburgh , Portland (OR), Raleigh/Durham, Reno/Tahoe, Sacramento, St. Louis, Salt Lake City, San Antonio, San Diego, San Francisco, San Jose (CA), Seattle/Tacoma, Spokane, Tampa, Tucson, Tulsa, Washington-Dulles C United Airlines Albuquerque, Austin, Baltimore, Billings, Boise, Boston, Cancún, Chicago-O'Hare, Cleveland, Columbus (OH), Dallas/Fort Worth, Des Moines, Honolulu, Houston-Intercontinental, Kahului, Kansas City, Kona, Las Vegas, Los Angeles, Miami, Minneapolis/St. Paul, New Orleans, New York-LaGuardia, Newark, Oakland, Oklahoma City, Omaha, Ontario, Orange County, Orlando, Philadelphia, Phoenix, Pittsburgh, Portland (OR), Puerto Vallarta, Reno/Tahoe, Sacramento, Salt Lake City, San Antonio, San Diego, San Francisco, San Jose (CA), San José del Cabo, Seattle/Tacoma, Sioux Falls, Spokane, Tampa, Tulsa, Vancouver, Washington-Dulles, Washington-National, Wichita Seasonal: Bozeman, Calgary, Eagle/Vail, Jackson Hole, Lihue, Mexico City, Montrose B United Express operated by ExpressJet Airlines Amarillo, Dallas-Love, Fargo, Lubbock B United Express operated by GoJet Airlines Austin, Cincinnati/Northern Kentucky, Detroit, Grand Rapids, Kansas City, Oklahoma City, St. Louis B United Express operated by Shuttle America Albuquerque, Atlanta, Austin, Cedar Rapids/Iowa City, Columbus (OH), Dallas/Fort Worth, Des Moines, Edmonton, Grand Rapids, Houston-Intercontinental, Indianapolis, Louisville, Minneapolis/St. Paul, Moline/Quad Cities, Pittsburgh, Salt Lake City, San Antonio, Toronto-Pearson B United Express operated by SkyWest Airlines Albuquerque, Aspen, Austin, Bakersfield, Billings, Birmingham (AL), Bismarck, Boise, Bozeman, Burbank, Calgary, Casper, Cedar Rapids/Iowa City, Cleveland, Cody, Colorado Springs, Columbus (OH), Dallas/Fort Worth, Dayton, Des Moines, Detroit, Durango, Eagle/Vail, Edmonton, El Paso, Eugene, Fargo, Fayetteville (AR), Fresno, Gillette, Grand Junction, Grand Rapids, Great Falls, Gunnison/Crested Butte, Hayden/Steamboat Springs, Helena, Huntsville, Idaho Falls, Indianapolis, Jackson Hole, Kalispell, Knoxville, Lincoln, Little Rock, Madison, Medford, Memphis, Midland/Odessa, Milwaukee, Minot, Missoula, Moline/Quad Cities, Monterey, Montrose, Nashville, New Orleans, Oklahoma City, Omaha, Ontario, Palm Springs, Pasco, Peoria, Phoenix, Pittsburgh, Portland (OR), Rapid City, Redmond/Bend, Regina, Reno/Tahoe, Rock Springs, Sacramento, Salt Lake City, San Antonio, San Jose (CA), Santa Barbara, Saskatoon, Seattle/Tacoma, Sioux Falls, Spokane, Springfield (MO), Tucson, Tulsa, Vancouver, Wichita, Winnipeg Seasonal: Traverse City B United Express operated by Trans States Airlines Cedar Rapids/Iowa City, Omaha, St. Louis B US Airways Charlotte, Philadelphia, Phoenix B Busiest Domestic Routes from DEN (January 2010-December 2010) Rank City Passengers Carriers 1 Los Angeles, California 964,000 American, Frontier, Southwest, United 2 Phoenix, Arizona 921,000 Frontier, Southwest, United, US Airways 3 Las Vegas, Nevada 912,000 Frontier, Southwest, United 4 San Francisco, California 806,000 Frontier, Southwest, United 5 Chicago