Denver International Airport (DEN) serves as one of United Airlines’ major hubs. It is the largest airport by land area in the Western Hemisphere and the second largest in the world, behind King Fahad International Airport (DMM) in Dammam, Saudi Arabia. Located approximately 25 miles northeast of downtown Denver, it served a whopping 82.4 million passengers last year. Based on data from Cirium, an aviation analytics company, this article explores United Airlines’ longest Boeing 737 MAX 9 routes from Denver.