Twentynine Palms Strategic Expeditionary Landing Field or Twentynine Palms SELF (ICAO: KNXP, FAA LID: NXP) is a military use airfield located nine nautical miles (17 km) northwest of the central business district of Twentynine Palms, a city in San Bernardino County, California, United States. The SELF is the largest expeditionary airfield (EAF) operated by the United States Marine Corps.