Serving the greater St. Louis area, Lambert - St. Louis International Airport (STL) is located about 10 miles northwest of downtown. It is Missouri's busiest airport, handling about 12.4 million passengers in 2014. Ten carriers operate at the airport, including American Airlines, Delta Air Lines, Southwest Airlines and United Airlines. Passengers can fly non-stop between St. Louis and about 90 destinations in the United States, Canada and Mexico. The airport has four runways and two passenger terminals. Terminal 1 has four concourses – A, B, C and D – and it used by all commercial airlines except for Southwest. Terminal 2 has a single concourse (E) and is used exclusively by Southwest.