Hyder Seaplane Base (IATA: WHD, FAA LID: 4Z7) is a state owned, public use seaplane base located one nautical mile (2 km) southeast of the central business district of Hyder, a community in the Prince of Wales-Hyder Census Area of the U.S. state of Alaska. It is included in the National Plan of Integrated Airport Systems for 2011–2015, which categorized it as a general aviation facility. It shares its airspace with the nearby Stewart Aerodrome and Stewart Water Aerodrome and its water runway in the Portland Canal exists on the Canada–United States border.