United Airlines’ main base of operations at Denver International Airport (DEN) is Concourse B. Considering that United has a significant hub at DEN, this concourse is among the busiest at the airport. The bulk of the gates in Concourse B are occupied by United Airlines DEN Terminal which offers a variety of dining and retail options in addition to United Club lounges for MileagePlus members and premium passengers, as well as a United Polaris lounge for international travel. Dedicated security checkpoints, self-service kiosks for luggage drop, and a simplified travel experience are available to United passengers traveling out of Denver International Airport.Â