Denver International Airport (DEN) is located 23 miles Northeast of Downtown Denver, within the city of Denver in the state of Colorado. It is United Airlines’ gateway to the Rockies, the Northern Plains, and it provides connections within the Mountain West, North/South, and East/West traffic flows. It is currently United Airlines’ (UA) largest hub, using data between April 2024 and April 2025. In the article below, we will look at the ins and outs of United’s Denver hub from both its local dynamics to the need it fulfills for United itself.
About Denver
As of the 2023 demographic numbers provided by data.census.gov, the Denver-Aurora-Centennial metro area has 371,233 foreign-born residents. This makes it the 24th largest metropolitan area for foreign-born residents. Denver’s largest immigrant groups by country are Mexico, India, Vietnam, Ethiopia, and China. The Denver-Aurora-Centennial metro area increased in population of between 2018 and 2023, which represented a 2.4% population increase.
As of the end of 2023, the Denver metropolitan area had a GDP of $311.9 billion, which represented 16.5% growth between 2021 and 2023.
About United's Hub at DEN
- Population within 100 KM of DEN: 4.32 million
- Total passenger count at DEN between April 2024 and April 2025: 79,012,053
- Total passengers carried by United and its regional subsidiaries: 37,807,080
- Percentage of traffic at DEN carried by UA: 47.9%
Destinations Served...
At present, UA serves 158 domestic and 20 international destinations. Of those, 150 domestic and 14 international destinations are served year-round, with at least four flights per week.
United’s Overall Load Factor at DEN was 86.22% between April 2024 and April 2025. The highest LF routes from DEN on UA were (must have at least 36 yearly departures):
First the Highest...
- Boston (BOS): 93.21%
- Springfield (SGF): 92.62%
- Burlington (BTV): 91.89%
- Portland, ME (PWM): 91.65%
- San Juan (SJU): 91.44%
- Hartford (BDL): 91.38%
- Shreveport (SHV): 91.36%
- Knoxville (TYS): 90.99%
- Lincoln, NE (LNK): 90.95%
- Fargo (FAR): 90.67%
...and the Lowest.
- Liberal, KS (LBL): 66.03%
- Hays, KS (HYS): 59.02%
- Moab, UT (CNY): 57.97%
- Laramie (LAR): 54.03%
- North Platte, NE (LBF): 52.63%
- Vernal, UT (VEL): 47.71%
- Salina, KS (SLN): 47.15%
- Scottsbluff (BFF): 39.45%
- Devils Lake (DVL): 35.67%
- Dodge City (DDC): 28.70%
Connectivity
29,891 passengers connect at DEN on UA daily each way. Of those, 27,456 were making purely domestic connections, and 2,435 were making connections with an international component. These figures mostly represent United Airlines and its marketed flights, but also those that fly into DEN on another carrier to connect to United.
Fleet Breakdown at UA's DEN Hub
In April 2025, United averaged 482 departures a day from its DEN hub. Of these, 291 were mainline flights operated by United itself, and 191 were regional flights operated by United’s regional partners. This makes a 60.4% Mainline operation.
Denver as an O&D Market for United
United flies 21,894 daily O&D passengers from DEN daily, non-directionally averaged between April 2024 and April 2025 (PDEW).
- Of the 21,894 total O&D passengers, 19,879 passengers carried by UA to/from DEN are domestic O&D.
- Domestic O&D is up by 4,887 PDEW or 24.6% since 2019.
- Below are the largest domestic O&D markets carried by UA to/from DEN.
Domestic O&D to/from DEN by UA Hub...
- Chicago (ORD): 877
- Newark (EWR): 782
- Houston (IAH): 727
- San Francisco (SFO): 694
- Washington, DC (IAD): 669
- Los Angeles (LAX): 584
- Guam (GUM): 8
...and by non-UA Hub.
- Boston (BOS): 572
- Orlando (MCO): 531
- New York City (LGA): 493
- Phoenix (PHX): 492
- Las Vegas (LAS): 459
- San Diego (SAN): 423
- Austin (AUS): 332
- Santa Ana (SNA): 330
- Seattle (SEA): 326
- Dallas (DFW): 319
- Fort Lauderdale (FLL): 292
- Tampa (TPA): 275
- Portland (PDX): 251
- Minneapolis (MSP): 246
- Philadelphia (PHL): 226
- Nashville (BNA): 212
- Salt Lake City (SLC): 211
- Miami (MIA): 206
- Cleveland (CLE): 203
- Sacramento (SMF): 202
- UA carries 2,015 international O&D passengers on average, non-directional, daily to/from DEN.
- This is up by 858 PDEW or 42.6% since 2019.
- Below are the largest international O&D markets to/from DEN by passengers carried by UA.
Top International Leisure Destinations by O&D...
- Cancun (CUN): 296
- San Jose del Cabo (SJD): 122
- Puerto Vallarta (PVR): 100
- Liberia (LIR): 59
- San Jose, CR (SJO): 26
....and top non-Leisure based International Destinations.
- London (LHR): 139
- Vancouver (YVR): 121
- Calgary (YYC): 89
- Toronto (YYZ): 81
- Edmonton (YEG): 52
- Frankfurt (FRA): 37
- Tokyo (NRT): 36
- Munich (MUC): 33
- Rome (FCO): 21
Largest Markets Unserved by UA at DEN: Domestic
- Dallas (DAL): 755
- Houston (HOU): 601
- Chicago (MDW): 538
- Long Beach (LGB): 165
- Providence (PVD): 52
Largest Markets Unserved by UA at DEN: International
- Guadalajara (GDL): 127
- Paris (CDG): 97
- Dublin (DUB): 74
- Amsterdam (AMS): 63
- Reykjavik (KEF): 57
The Present and Future of UA's Hub at DEN: what is and what is possible.
Beyond O&D, DEN’s primary purpose is to serve as the powerhouse of United’s domestic network. It handles domestic traffic flows from both North/South and East/West directionality very well. Unlike UA’s other hubs, where international traffic is a significant part of their network, domestic traffic is 93.8% of the seat count at UA’s DEN hub. UA offers roughly half of the international seats out of DEN that they do at ORD or IAD, but most traffic is domestic and DEN is a (if not the) prime candidate for any new domestic service on UA. So, what does this mean for the hub?
DEN is, debateably, the best domestic-focused hub an airline could have.
The geography speaks for itself. DEN is at the geographic center of the United States, west of the Mississippi River. It is neither too far north nor south, allowing it to handle East/West flows seamlessly. It is at the base of the Rocky Mountains, but also located on the Great Plains, allowing it to handle short-distance connections between small towns in the region. Small towns in the Rocky Mountains and Northern Plains tend to have high fares and can be operated with smaller aircraft that have a lower cost to fly. This would certainly maximize yields on such routes.
DEN's Domestic O&D market size is massive
Denver’s business market, leisure appeal, and being the only major airport for hundreds of miles around create the perfect combination of factors for a massive O&D base. As of April 2025, DEN is the 4th largest O&D airport in the US by domestic demand. This allows UA to take chances at DEN with domestic destinations that they might not be able to do at other hubs. Being such a large domestic O&D market with a sizable leisure component and ample connection opportunities allows new flights to DEN to mature more easily than most other airports.
The data shows that DEN is the largest hub in total, but specifically because of the domestic traffic. DEN has a good mix of domestic connections and O&D. It is an efficient hub to operate from, with a great geographic location to funnel traffic through.
However, the international data does show DEN in a bit of a different light.
Whereas DEN is the largest domestic hub for UA, it’s the 2nd smallest in onboards and the smallest in terms of O&D. There are several reasons for this:
- DEN’s geographic location is not conducive to international connections.
- DEN is, by a significant margin, the smallest UA hub airport for international O&D.
- DEN’s demographics contain little opportunity to grow international O&D due to its smaller immigrant population size relative to other UA hubs.
Limitations and Opportunities
UA’s hub network is arguably the most international among all US carriers, as it carries more long-haul passengers than any other US carrier. It is a close 2nd to American Airlines (AA) in terms of total international passengers carried when short-haul international is included. DEN as an airport and Denver as a city are the least international of their hubs and hub cities, though. DEN is also the only UA hub that has yet to (as of now) gain a Polaris lounge for long-haul premium travel, and DEN’s elevation also creates its own complication for long-haul flying.
Because of this, DEN will not be first in line for any new international service, but that doesn’t mean there aren’t opportunities for UA at DEN. Any new future opportunities at DEN would have to fit a few of the criteria listed below:
- Already served from other UA hubs
- Have a widely dispersed demand among many US cities and regions.
- The destination is a hub for a carrier that has a close relationship with UA (preferably a JV).
- The US point of sale is dominant as opposed to the foreign point of sale.
- Have a premium leisure component
New opportunities like the recently launched DEN-Rome (FCO) fit in nicely. It’s a heavy US point of sale, it’s served by other UA hubs, and there is a large premium leisure component. Other routes like Barcelona (BCN) could also be in the cards with this strategy.
The opportunities for DEN outweigh its limitations. It is a growing market, the airport infrastructure is there, and UA has been very effective at keeping its competition (predominantly Southwest Airlines) at bay in DEN. Its strategy at DEN has paid big dividends. They are the market share leader, and their O&D share has grown tremendously. But DEN is not going to be comparable to Atlanta (ATL) or Dallas (DFW). The opportunities for international travel are just not there in order to replicate those two mega-hubs, but that does not mean it cannot continue to fortify and grow as a domestic powerhouse with a sizable international network. The continued focus will be on adding North American destinations and maximizing connectivity. In the end, while focus is often placed on long-haul flying, that isn’t where the majority of money is usually made for an airline. Domestic and short haul flying usually has the most opportunities, and DEN, more than almost any other airport, is able to capitalize on that.