Whetstone International Airport or Del Bonita/Whetstone International Airport (IATA: DJN, FAA LID: H28, TC LID: CEQ4) is a public use airport at the Canada – United States border, in Port of Del Bonita, Glacier County, Montana, 2 nautical miles (4 km) south of Del Bonita, Cardston County, Alberta. The airport is owned by the U.S. state of Montana and operated by the Montana Department of Transportation Aeronautics Division.