Nickajack Cave is a large, partially flooded cave in Marion County, Tennessee. It was partially flooded by the Tennessee Valley Authority's Nickajack Lake, created by the construction of Nickajack Dam in 1967. The entrance was originally 140 feet wide and 50 feet high. There is now about 25–30 feet of water at the entrance, so the portion of the entrance above water is 140 feet wide and 20–25 feet high. It houses a large colony of gray bats, an endangered species, and the water levels have posed a danger to the bat colony. The cave took its name from the Chickamauga Cherokee town of Nickajack, located between its mouth and the Tennessee River. The town was once attacked and destroyed in 1794 by the Nickajack Expedition. Cultural history Nickajack Cave was mined for saltpeter by James Ore beginning in 1800. At this time, the cave was on land owned by the Cherokee and this operation was conducted with their permission. This mining continued through the War of 1812. The cave was again mined for saltpeter during the American Civil War, this time by the Confederate Nitre and Mining Bureau. Page 85 of the February 6, 1864 issue of Harper's Weekly shows a drawing of the cave entrance and some of the saltpeter mining and refining equipment located outside the cave. Robert Cravens, a Chattanooga businessman, operated Nickajack Cave and his own cave, Lookout Mountain Cave at the beginning of the Civil War. Soon after the war started, the operation at Nickajack Cave was taken over by the Confederate government. Some time in late 1863 or very early 1864, this area was occupied by Federal troops and mining ceased. Nickajack Cave was one of the largest saltpeter caves operated by the Confederate Nitre Bureau during the Civil War and, as such, was a highly strategic site, since saltpeter was the main ingredient of gunpowder. The loss of Nickajack Cave was a serious blow to the Confederacy. Musician Johnny Cash visited the cave in 1967, intending to commit suicide inside it, but had a spiritual experience there that caused him to stop his habit of drug abuse. Country singer Gary Allan recorded a song about this experience on his 2005 album Tough All Over. Nickajack Cave was commercially exploited, off and on, since at least 1872. At that time, a newspaper clipping dated July 2, 1872 describes tours leaving from Chattanooga on