It is one of the largest gray bat colonies in the Southeast. It is free to watch. And it is in Marion County, Tennessee.

Here is everything you need to know to see it — including the part of the story involving Johnny Cash.

Why Are There So Many Bats?

The residents are gray bats (Myotis grisescens), a federally endangered species. Unlike most bats, gray bats live in caves year-round rather than roosting in trees or attics, which makes them enormously dependent on a small number of suitable caves — and Nickajack is one of the good ones.

Estimates for the summer colony run into the tens of thousands, with the upper end of published figures reaching around 100,000 animals. They spend the day inside, and at dusk they leave en masse to hunt insects over the lake and the surrounding river gorge. A single gray bat can eat thousands of insects a night. Multiply that across the colony and you understand why the mosquito situation on Nickajack Lake is better than it has any right to be.

The cave itself has a long human history. It was mined for saltpeter — a key ingredient in gunpowder — during the Civil War, and it was a well-known local landmark long before that. In 1967 the Tennessee Valley Authority impounded Nickajack Reservoir, which flooded the lower cave passages permanently. The colony survived, and the entrance was later gated and designated a wildlife refuge specifically to keep people out and bats in.

Option 1: Watch for Free From the Boardwalk

You do not need a boat. There is a short, easy walkway and viewing area at the Maple View Public Use Area that looks out toward the cave entrance across the water. It is flat, it is quick, and it costs nothing.

What to expect: park, walk a few minutes, and find a spot along the rail. As the sun drops, the first few bats trickle out — then the trickle becomes a stream, and the stream becomes a steady dark ribbon flowing out over the lake. On a good night in midsummer it does not stop for forty-five minutes.

Free-viewing tips

• Get there early. Thirty minutes before sunset gives you a parking spot and a good place at the rail. Summer weekends draw a crowd.
• Bring bug spray. The bats are working on it, but they have not finished.
• Bring a red-filtered flashlight if you have one. White light disturbs the colony and ruins everyone's night vision.
• Skip the flash. Phone flash will not reach the cave anyway, and it bothers the animals.
• Be quiet. You can hear them — a papery, rushing sound — but only if the crowd cooperates.

Option 2: See It From a Kayak

The boardwalk is good. The water is unforgettable.

Several Chattanooga-area outfitters run guided sunset paddles on Nickajack Lake timed to the emergence, typically launching from a public ramp in the South Pittsburg area and covering an easy few miles of flat water before parking the group in front of the cave for the show. Guides handle the timing, the route, and the safety end of things, which matters because you are finishing in the dark.

Because the tours run seasonally and sell out through the summer, book well ahead rather than driving up hoping for a spot. Search for a Nickajack bat cave kayak tour and compare current operators, dates and pricing directly — schedules shift with the season and the water level.

What the paddle is actually like

• Difficulty: Beginner-friendly. Nickajack is a reservoir, so it is flat water, not whitewater.
• Distance: Typically around three miles round trip at a relaxed pace.
• Wildlife bonus: Osprey are common overhead, great blue herons work the shoreline, river otters turn up, and bald eagles are a genuine possibility on this stretch of the Tennessee River.
• Dress for wet: Quick-dry clothes, secured shoes, and a dry bag for your phone.

The Johnny Cash Story

Nickajack Cave has one more claim on the American imagination.

As Johnny Cash told it in his 1997 autobiography, he came here in 1967 at the bottom of a years-long amphetamine addiction, intending not to come out. He crawled into the cave with a flashlight and kept going until the batteries died, then lay down in total darkness to wait. Instead of dying he described a moment of clarity — the sense that his life was not his to end — and began crawling, with no light and no sense of direction, toward what turned out to be the entrance. He wrote that his mother and June Carter were waiting outside with a basket of food, saying they had known something was wrong.

He got sober not long after. It is one of the most retold conversion stories in country music.

Historians note the account did not appear in his earlier 1975 memoir and surfaced only thirty years after the fact, so treat it as the story Cash chose to tell about himself rather than as documented history. Either way, standing on that shoreline at dusk, it lands.

Make It a Whole Evening

The emergence takes about an hour, which leaves you with a beautiful summer evening in Marion County and no plan. Some easy pairings:

• Eat first in South Pittsburg or Jasper. You will finish at the cave after dark and most small-town kitchens close early — get dinner in before the show, not after. Our restaurant directory lists what is open, town by town.
• Add a morning on the water. Nickajack Lake is the same body of water — boat ramps, fishing, and a shoreline that stays quiet on weekdays.
• Pair it with a waterfall. Foster Falls is a 60-foot drop with a swimming hole at the bottom, less than an hour away.
• Go full spooky. The Hales Bar Dam — routinely called one of the most haunted places in the South — is on the same lake.

Frequently Asked Questions