Houghton County Memorial Airport (IATA: CMX, ICAO: KCMX, FAA LID: CMX) is a county owned public use airport located four nautical miles (5 mi, 7 km) southwest of the central business district of Calumet, a village in Houghton County, Michigan, United States. The airport is situated in the unincorporated community of Oneco in Franklin Township, near the village of Calumet on the Keweenaw Peninsula in northwest of the Upper Peninsula of Michigan. A limited scheduled commercial service is available, subsidized by the Essential Air Service program. In addition, Royale Air Service provides a seaplane service to Isle Royale National Park depending on traveler demand.