Underground Time Travel

Getting to Mammoth Cave National Park isn’t easy, especially in the dark. From Western North Carolina, anyway, the trip involved hours of off-highway driving through hills punctuated by struggling Kentucky coal towns before reaching the park, where white-tailed deer leapt out of the night at every turn and GPS instructions to the campground—which of course turned out to be full—directed us to drive straight into the river. It was midnight before we stumbled upon a private campground with a place to pitch our tents. 

With our first of three cave tours booked for 8:45 the next morning, I must admit there was a larger-than-tiny part of me that wondered if would all prove worthwhile. I do love my sleep, after all. 

But when the sun got up, so did I, throwing on some clothes and packing a bag that included plenty of layers for the cooler underground temperatures. Our guide led us down a set of 70 steps through the gaping cave entrance, opening into a spacious subterranean world remarkably immune to the reality of the Kentucky October above. High ceilings rose above the cavern’s wide-set walls, the natural result of years of water eroding limestone rock. That water is mostly absent these days—Mammoth Cave has more dust than moisture. 

In fact, I learned, that dust is an important part of its history. The cave was instrumental to the U.S. victory in the War of 1812 when it became the largest producer of a key ingredient in saltpeter, which was used to make gunpowder. About half the bullets used in that war contained dust from Mammoth Cave, and the cave’s historical importance led to its designation as a national park in 1941—it would be years later before anyone figured out that it was also the world’s longest known cave system, with 405 surveyed miles. 

Paid labor wasn’t responsible for Mammoth Cave’s contribution to winning the War of 1812, however—slaves were tasked with extracting the saltpeter ingredients from cave dust, and when the war ended the cave’s owners turned to tourism to make a buck. Some of the former saltpeter miners became tour guides, and the caves became the backdrop for a temporary inversion of the rules of Southern racial segregation and classism as the rich white people who came to see the caves with only candles to light the way found themselves putting their lives in the hands of their black tour guides. 

Time has marched on in the sunlit world above the caves, but down inside them it seems frozen, as though a cluster of candlestick-bearing gentlefolk in suits and dresses could round the corner at any moment, exclaiming in fear and awe at the dim illuminations of the candle flames. Original equipment from the saltpeter operation is still there, as are the rock piles and candlesmoke graffiti left behind by those early tourists. 

I found it all fascinating, but also a bit sad that even here, far below the earth’s surface in an environment of perpetual darkness, man has managed to leave such a permanent mark. 

But that’s not the case everywhere in Mammoth Cave. Of its 405 mapped miles, I’d explored only about two of them, the ones closest to the entrance. There are tens and hundreds of miles that only a select few world-class spelunkers have seen, and who knows how many more just waiting to be discovered. In a world where even the most remote deserts and mountains are so well mapped, that’s nothing short of remarkable. Goosebump-inducing, really. 

The third tour gave me at least a taste of what the cave was like beyond the reach of the early miners and tourists, though of course it still held the infrastructure of stairs and electric lights for we modern visitors. The route wound through narrow, low-roofed passageways linking the larger caverns and eventually led to a vertical opening so high I couldn’t quite see the roof. My jaw dropped, and my body froze. Though standing on a platform large enough to hold only a small fraction of the tour group at one time, I found myself unable to do the polite thing and move along after catching a quick look. It was the same feeling that comes over me every time I see a waterfall, that optical magnetism that leaves me perfectly happy to spend minutes and probably even hours just standing and staring. 

I remembered what I’d read in the visitor center about the cave having five main vertical levels, and I wondered how many were now within my view. Water was falling from somewhere just out of sight, the sound like that of rain on a stone walkway. I looked up again, trying to see where it came from. A single drop of water, catching light that colored it pearly white, fell as I watched.

Eventually I did force myself to move, following the guide to the cave exit. The heat and humidity of the Kentucky afternoon hit me like a wall, fogging my glasses and forcing an immediate retreat from the layers that had been so necessary under the ground. 

I wiped my lenses, surprised to see the fading greenery of early October before me. In Mammoth Cave, hours—and even centuries—can slip away unnoticed.