What is Sistema Huautla? The PESH Exploration series continues

To Seek the Deep - PESH Huautla expedition 2015

This is the second in our series of posts following the 2015 PESH Expedition to Sistema Huautla.
Read the first post here, or the next one here.

Whole Earth Provision Co. is a proud supporter of Proyecto Espeleológico Sistema Huautla or PESH for their 2015 expedition to explore the deepest cave in the Western Hemisphere – Sistema Huautla.

In the 1960s, cavers suspected that the Sierra Mazateca, located in northeast corner of the state of Oaxaca in Mexico, harbored caves of great interest. The geology was right and there were enormous crevices that opened deep into the earth. Rocks tossed into the openings took so long to reach “bottom” that would-be explorers knew that climbing skills were going to be essential for any exploration.

At first, the cavers believed that they were exploring several large caves. But as the caves were mapped by successive expeditions, it became clear that they were in very close proximity to one another, so the search was on to find connections between them. Eventually Sótano de San Agustin was connected to La Grieta, Nita Nanta , and eight other cave entrances to create Sistema Huautla, the deepest cave system in the Western Hemisphere, 5069 feet from top to bottom, with over 40 miles of mapped passageways.

Huautla Cave System map

Huautla Cave System Map coutesy of PESH

The map of Sistema Huautla looks as if it were drawn by Dr. Seuss. Long tendril-like shapes twist and turn in unexpected directions as they course downward through the mountains. Many of these passageways were carved by water. The Sierra Mazateca catches the moisture carried by winds coming off the Gulf of Mexico, drenching the mountains with heavy rains. During the rainy season the waterways within the Sistema become raging torrents, causing expeditions to plan carefully to avoid, if possible, the threat of being caught in an underground flood.

Sistema Huautla map with Pena Colorada

click image to view full-size version

Above: Map from Hydrogeology of the Sistema Huautla Karst Groundwater Basin by James H. Smith Jr. AMCS Bulletin 9 p. 85. Yellow line marks a compressed view of the gap between the two portions of Sistema Huautla.

The flow of water through Sistema Huautla can be imagined in the shape of a tree. At the top there are small branches that join together to form ever larger limbs, eventually joining the trunk of the tree. Rainwater finds its way into the mountains and runs as subterranean streams, rivers and waterfalls and settles into pools and tunnels, called sumps, as it makes its way to Cueva de la Peña Colorada which empties into the Santo Domingo Canyon. A 3.41 mile section between Sistema Huautla and the Cueva de la Peña Colorado remains a question mark on the map that hopefully will be filled in by PESH one day.

Bill Steele, the expedition’s co-leader, believes that Sistema Huautla is “probably the best cave on earth – lots and lots of variety.” * It contains passageways so narrow that they are truly the stuff of nightmares, as well as canyons, vertical shafts that could swallow large buildings, 60 story waterfalls and chambers, one of which is large enough to hold a domed stadium. The Sistema also has its fill of geological formations and wonders, the greatest of which may be the magical anthodites. These rare, needle-like crystals grow in clusters that radiate from a common base like flowers and grow downward from the ceiling.

Mike Futrell with rare anthodites

Above: Mike Futrell with rare anthodites – photo from Huautla: Thirty Years in One of the World’s Deepest Caves by Bill Steele

Soon we’ll be looking at what it takes to explore a deep cave. In the meantime, you can follow the PESH expedition on their Facebook page.

This is the second in our series of posts following the 2015 PESH Expedition to Sistema Huautla.
Read the first post here.


*  Bill Steele quote from Men’s Journal. Read the full article here, or the next one here.