DEN: Denver International Airport survival guide
Denver International is enormous and far from downtown. Security is in the main terminal, and an underground train connects to Concourses A, B, and C, so allow time for the trip between them.
Last checked October 2026. Confirm details on Denver International Airport (official).
DEN at a glance
| Layout | Main terminal plus Concourses A, B, and C |
|---|---|
| Between concourses | Underground train (Concourse A is also reachable by a bridge) |
| Public transit | A Line train to Union Station downtown |
| Biggest airlines | United (Concourse B) and Southwest (Concourse C) |
Tips for DEN
- The airport is about 25 miles from downtown. The A Line train avoids traffic.
- Check security wait times before you go. Lines vary a lot by checkpoint.
- Walk the bridge to Concourse A if the train is packed. It has views.
- Snow happens. Give winter trips extra buffer.
Universal airport tips
- TSA PreCheck usually means shorter lines, and you keep your shoes on.
- Screenshot your boarding pass in case the app or Wi-Fi fails.
- Know your rights before something goes wrong: refunds, bumping, and lost bags.