What Terminal is Southwest Airlines at LAS? Southwest Airlines' primary operating base is located in Terminal 1 of Harry Reid International Airport (LAS), formerly known as McCarran International Airport. To enhance passenger comfort, Terminal 1, the domestic aviation hub, provides a multitude of amenities. The airline Southwest uses the B and C gates of this facility. In Terminal 1, travelers on Southwest may take advantage of speedy security checks, easy check-in processes, and a range of dining and shopping options. Because the terminal is connected to the rest of the airport via a shuttle system, passengers on connecting flights may move around it with ease.