Mountainburg is a city located in the U.S. state of Arkansas. It is within Crawford County included in the Fort Smith, Arkansas-Oklahoma Metropolitan Statistical Area. It has a total area of 1.51 square miles at 35°38′18″N 94°10′2″W. The elevation is 751 feet above sea level. As of the 2010 census data, it had a total population of 631. The population density was 411.88/sq mi. Estimated per capita income in 2015 was $18,856. Recent job growth is positively increased by 2.07 percent. The average travel time is 19 minutes. It has Zip code 72946.