In 1965, a handful of college students in Austin, Texas, asked their geology professor a simple question: Where would you look if you wanted to find the deepest cave in North America?
Their investigation pinpointed Huautla de Jiménez, a remote town in Oaxaca, Mexico. What was it about this spot that caught their attention?
“It was the local limestone,” Bill Steele, a longtime caver and Explorers Club member, told me. “It’s around two kilometers thick. Then there’s the rainfall — about three meters a year, that’s 118 inches! But there aren’t any surface streams in the area. So where was all that water going?”
The following year, four Austin cavers drove south to find out, and ended up rappelling into the astoundingly beautiful Sótano de San Agustín (St. Agustine’s Basement). “Here we are now, 60 years later, and we’ve got the deepest system of caves in the Western Hemisphere — 1,560 meters deep,” Steele said. “Up until this year, it was explored and mapped at 101 kilometers in length. When we process this year’s data, it may surpass 105.”
According to Steele, Sistema Huautla has 30 entrances, immense rooms, stunning crystalline formations, waterfalls, and underground rivers. “It’s been called, by people who know, the world’s most magnificent cave,” he said. “And our best hunch is that we’ve only found half of it.”
One week underground
To promote further exploration of the system, Proyecto Espeleológico Sistema Huautla (PESH) was founded in 2014 and typically organizes cave studies every April. This year, 59 volunteers came to Huautla from Mexico, the United States, England, Poland, Australia and Costa Rica. Four teams of the hardiest explorers camped underground for a week at a time, each following up on leads discovered in previous years.
“They’re completely out of contact with the outside world,” Steele told me. “There’s no radio that works through that much rock, so they tell us when they expect to get out, and if they don’t show up, we go looking for them.”
Alongside the explorers and mappers are the scientists. “We follow the philosophy of the people who explore Mammoth Cave, the world’s longest,” Steele said. “This means that while you’ve got the best explorers — and all the right equipment — in the cave, you should take advantage and do all the scientific studies possible.”
The results have included theses on the system’s geology, biology, and paleontology, as well as an archaeological study of rain-god rituals once held in some of the caves. “They’re also doing studies of paleoclimatology,” Steele said. “It turns out there are datable traces of minerals in stalagmites, so if you find one that’s fallen over in an earthquake long ago, you can bring it out for analysis. A professor in Las Vegas has used these to learn far more about the climate of southern Mexico than was previously known.”
A scorpion named Steve
Among Sistema Huautla’s many contributions to science is Alacran tartarus, a blind scorpion found around 800 meters below the surface — the world’s first known troglobitic scorpion, described by renowned Mexican biologist Dr. Oscar Francke in 1982.
This year, UNAM professor Edmundo González asked Steele for a favor: could the cavers find a live specimen and get it all the way to Mexico City? A study of the venom of these cave-adapted scorpions, González explained, might lead to a new antivenom.
“By good luck, a couple from Georgia did come across this cave scorpion, deep underground,” Steele said, “and they brought it to the surface in a half-liter bottle, opening it every few hours to splash in a little water. Then I put it into a ‘critter box’ lined with black paper. All the cavers liked that little scorpion so much, they named it Steve — after Steve Zeman, the camp cook, whose food everyone adored.”
The couple carried Scorpion Steve to Mexico City by bus and finally by taxi to UNAM, where they handed him over to Professor González. So far, Steve is alive and healthy — the first time a cave-adapted scorpion has ever been kept alive on the surface.
Collecting experiences
PESH is a non-profit, and participants pay their own way. The cavers have also supported local initiatives, including the printing of materials in the Mazatec language.
Even so, rumors occasionally circulate about why so many foreigners keep coming to this remote corner of Oaxaca.
“I was in a pottery shop in the little town of San Andrés,” Steele told me, “and the proprietor came over and said, ‘People say you guys take things out of the caves.’”
For years, Steele had simply denied it. This time, he tried something different.
“Yes, that’s true,” he told the man. “Actually, we take three things out of the caves. Number one, knowledge of what’s down there, so we can share it with the Mazatec people, who don’t have the equipment or experience to go in themselves. Number two, photographs of what we see, so we can share that beauty with you. And number three: experiences, which enrich our lives.”
To Steele’s surprise, it was the third one that made the man smile. “On reflection, I understood,” he said. “These people don’t live in the world community. It’s their everyday experiences that make up their lives. These are things they appreciate.”
To share in the experiences of the Huautla cavers, visit PESHcaving.org.