The largest airport in the United States of total area 13726 ha and second largest in the world Denver International Airport is hub for major airlines like United Airlines, Frontier Airlines, and Great Lakes Airlines. City and County of Denver Department of Aviation owned and operated airport has 31,004,575 annual passengers and 635,445 flights operation which is pretty high in actual because the data has been verified since 2012. Denver International Airport has named as Best Airport in North America and America’s Best Run Airport by well known magazine of United States.