What Terminal is Southwest Airlines at LAS in Las Vegas. This terminal accommodates all the Southwest Airlines flights, and check-in desks are always available at Level 1. Passengers board from the B and C gates, which may be accessed by the free Blue Line tram, powered by Allegiant. Terminal 1 offers a variety of dining options, shopping, free Wi-Fi, and expedited TSA security. With seamless facilities and ground transportation options, Terminal 1 offers Southwest Airlines passengers a seamless experience.