The term LEAD-IN TO VEGAS is solved by the three letter answer LAS, which stands for the Las Vegas McCarran International Airport. This airport is the main airport serving the Las Vegas Valley and is located in Paradise, Nevada. It is the busiest airport in the state of Nevada and the eighth busiest airport in the United States. The airport serves as the primary gateway to Las Vegas and is a major hub for Allegiant Air, Southwest Airlines, and Spirit Airlines.