Portland International Airport is a joint civil-military airport and the largest airport in the U.S. state of Oregon.It is located within Portland's city limits just south of the Columbia River in Multnomah County. Before the 1930’s, airports had two-letter codes. When codes switched to three letters, many added the letter ‘X’ to the end so PD (PortlanD) became PDX.
Portland International Airport code (PDX)
Airport Name: Portland International Airport
Airport Keywords: Portland Intl
Airport (IATA) Code: PDX