Claire L. Evans is the author of Broad Band: The Untold Story of the Women Who Made the Internet.
The longest cave in the world is in central Kentucky. Its limestone passages stretch 400 miles beneath the earth in twisting patterns as intricate as the roots of the ancient hickory forests above. Within, cavers skirt bottomless pits, pass fountains of orange stone, and discover deep, icy subterranean rivers. Between the sunlit world and the depths below, white mist swirls at ankle height, like the breath of ghosts.
Kentuckians have fought bitterly to control access to the secrets of Mammoth Cave. In the early 20th century, hardscrabble locals conned tourists into the sinkholes on their land, spurring “cave wars” that ceased only when the National Parks Department took control, evicting landowners and installing staircases, subterranean toilets, and even a grand dining room 267 feet below ground, its ceiling encrusted with snowballs of gypsum crystal. Serious cavers now enter Mammoth’s wild entrances through locked grates, using keys granted by the Parks Department. They bring with them small carbide headlamps to keep warm and light the darkness.
The earliest people to map Mammoth were enslaved, installed underground by landowners to lead tours. The ﬁrst of these guides, Stephen Bishop, named its features — the River Styx, the Snowball Room, Little Bat Avenue — and discovered the eyeless white ﬁsh that swim in its deepest waters. When Bishop was sold, along with the caves, to a Louisville doctor, he was ordered to draw a map from memory. As cave maps do, his drawing looked like “a bowl of spaghetti dumped on the ﬂoor,” but it detailed the nearly 10 miles of passages that Bishop had discovered and remained the most thorough map of Mammoth’s reaches for more than 50 years. One nameless noodle, a passage forking off the subterranean Echo River, became important a century after Bishop was buried near the cave’s main entrance, his grave marked by only a cedar tree.