Dane County Regional Truax Field — Madison, United States

MSN, the IATA code for Dane County Regional Airport (Truax Field), serves Madison, the capital of Wisconsin, and the surrounding Dane County area. The airport shares its grounds with a Wisconsin Air National Guard base, reflecting its dual civilian-military heritage dating back to World War II training operations. Today MSN handles regional and mainline domestic flights, connecting Madison to major hubs like Chicago, Minneapolis, and Denver. It also supports general aviation, cargo operations, and university-related travel given the airport's proximity to the University of Wisconsin-Madison. Terminal upgrades in recent years have expanded gate capacity to keep pace with the city's steady population and tech-sector growth.