Last updated: April 18, 2026
- Lake: Nickajack Lake (TVA reservoir, ~10,370 acres at full pool)
- Cave: Nickajack Cave, partially flooded since 1967
- Dam: Nickajack Dam, completed 1967 (replaced Hales Bar Dam)
- Operator: Tennessee Valley Authority (TVA)
Three features in southern Marion County share the Nickajack name: a TVA reservoir, a large limestone cave, and the dam that links them. All three sit along the Tennessee River where it passes through the Tennessee River Gorge toward the Alabama state line. The name comes from the Cherokee Lower Town of Nickajack, which stood in the same area in the late 18th century. Read more about Nickajack & Running Water →
Nickajack Dam
Nickajack Dam was completed by the Tennessee Valley Authority in 1967, replacing the older Hales Bar Dam (1913) about six miles upstream. Hales Bar had been built privately by the Tennessee Electric Power Company but suffered from chronic leakage through karst limestone in its foundation; TVA chose to build a new dam at a more stable site rather than continue patching the original.
Nickajack Lake
Nickajack Lake is the reservoir formed by Nickajack Dam. It extends roughly 46 miles upstream to Chickamauga Dam, covering parts of Marion and Hamilton counties in Tennessee and a small portion of Alabama. The lake supports recreation, boating, fishing, paddling, and provides hydroelectric generation, navigation, and flow regulation as part of the TVA river system.
Nickajack Cave
Nickajack Cave is a large limestone cave on the south bank of the Tennessee River. Its lower passages were partially flooded when Nickajack Dam raised the river level in 1967. Today the cave entrance is gated by TVA to protect a colony of gray bats (Myotis grisescens), a federally endangered species. Summer evening bat emergences can be viewed from a public TVA observation platform across the inlet from the cave.
Layered history
The cave has accumulated several distinct chapters of human use:
- A Cherokee Lower Town (Nickajack) was located near the cave in the late 18th century.
- Saltpeter was mined from the cave during the War of 1812 and the Civil War.
- The cave is associated with stories of being a refuge for runaway enslaved people during the antebellum era.
- Johnny Cash described entering the cave in 1967 intending to die and emerging with a religious experience that began his recovery from addiction. Read more about the Cash episode →
Related
About the Tennessee River Gorge →
About “The Suck” rapids →
About Nickajack & Running Water →