Sloulin Field International Airport (IATA: ISN, ICAO: KISN, FAALID: ISN) was an airport serving Williston, a city in North Dakota. It was two miles north of downtown and was owned and operated by the city.[1][2] Built in 1947, the airport faced expansion constraints, design issues, and the need for runway refurbishment. For these reasons, as well as the rise in air traffic amid the North Dakota oil boom, officials decided to build Williston Basin International Airport. Sloulin Field Airport closed to the public on October 10, 2019.