Frontier Airlines Harry Reid International Airportleaves from Terminal 3 at Harry Reid International Airport in Las Vegas, but it's a much more contemporary and efficient way to travel. Terminal 3 is known for having easy access to security checkpoints with streamlined check-in while offering multiple dining and shopping spots throughout to enhance your trip. Frontier passengers are encouraged to arrive 2 hours prior to domestic and 3 hours prior to international flights for easier check-in and boarding. For business or fun, Frontier Airlines at LAS gives all passengers ease and comfort.