Denver airport marks a milestone anniversary with solid passenger growth and promising prospects

Denver International Airport marks an important milestone in 2015, celebrating its 20th anniversary on a good note after reaching its highest passenger levels in four years during 2014. The airport also marked a banner year in 2013 when United inaugurated Denver's first service to Asia with the launch of flights to Tokyo Narita.

The airport has a good representation of all the airlines business models, serving as a hub for United, Southwest Airlines' fourth largest base measured by ASMs and ULCC representation from Frontier Airlines, which is headquartered in Denver, and Spirit.

But obviously the airport is not resting on its laurels as it reaches its anniversary. It is in intense competition with other airports to secure additional long-haul flying, angling for service to Asia and Europe and perhaps flights to the Middle East and South America.