Big Mountain in southeastern Oklahoma rises 1,145 feet in Pushmataha County within the Kiamichi Mountains and forms the southern edge of Johns Valley, bounded by Buck Creek, Pine Creek, the Kiamichi River, and Kimbrough Creek. Once also called Deer Mountain, it is best known historically for a World War II-era tragedy in which British pilots training from a Royal Air Force base in Texas crashed at White Rock Mountain and Big Mountain, killing four crewmen. In 2000, the AT6 Monument was dedicated at the Big Mountain crash site. Big Mountain also serves as the gateway to the isolated Kiamichi Wilderness, where scattered settlement has slowly developed.