In Las Vegas, Harry Reid International Airport (LAS) is where you will find Alaska Airlines primarily operating out of Terminal 3 (Concourse E). This terminal sees both domestic and international arrivals and is modern, spacious, and generally easy to navigate. If you are flying Alaska Airlines, your check-in, security, and flight will likely depart from Terminal 3. That said, if your ticket says Alaska Airlines but the flight is operated by a partner airline, you may potentially leave from Terminal 1. So before heading out to the airport, it’s good practice to confirm your flight details if booked through Alaska Airlines.