DLH (Duluth International Airport) is a city owned, public use joint civil-military airport located 5 nautical miles northwest of Downtown Duluth. Mostly used for general aviation but also served by three airlines, it is Minnesota's third-busiest airport, behind Minneapolis–St. Paul International Airport and Rochester International Airport.
Aircraft manufacturing company Cirrus is also based on the airport grounds, where it has its main manufacturing facility and headquarters.
Live Air Traffic Map
Here you can see all of the planes flying to, from, and over Duluth.