photo: Anthodite Hall in San Agustin. Photo by Matt Tomlinson.

What and where is this cave?

In Southern Mexico the impressive Huautla Plateau rises to over 2000m. Beneath the surface the limestone mountain contain a monstrous network of caves and passages cut by water, which stretch from the plateau down to the Santo Domingo Canyon 10 kilometres away.

Huautla is something rather special, this cave means a lot to cavers all over the world, but particularly those in the U.S and UK. For the Americans who first came to the area, Huautla became an obsession. It was discovered in the 1960's and soon became the deepest cave in the Western Hemisphere. It is perhaps the most complex of the world's deep caves, with 17 entrances and numerous independent deep routes, going all the way down to a total depth of 1560 meters.

In 1994 American Dr. Bill Stone led an Expediton to Huautla to dive the then terminal sump. In order to make this logistically possible he developed the CIS Lunar rebreather, which is now considered the forerunner of widely available commercial rebreathers. The 1994 Expedition succeeded in passing the terminal sump and finding 3.3 kilometers of new passage beyond. However, the trip was marked with tragedy, during one of the exploration dives Ian Rolland sadly lost his life. When the 1994 expedition took place, it was the largest and most significant cave exploration expedition ever conducted. The team gave up months and months of time to make it possible, with Ian making the ultimate sacrifice. It is a testament to their achievements that it was not till 2013 that anyone has even contemplated returning.

A schematic of Sistema Huautla (on the left) relative to its resurgence (on the far right) and the Pena Colorada, it's hypothesised fossil overflow resurgence. Only the most convenient/quickest route to Sump 9 is shown.

At the other end of the Huautla Plateau in the Santo Domingo Canyon, the water which runs though the Huautla system re-emerges to the outside world. Between the ends of these explored caves a gap of more than four kilometers exists, a connection would make the system 90 km long. In the Santo Domingo Canyon, the fossil overflow resurgence to Sistema Huautla, known as the Cueva de la Pena Colorada, intersects the Huautla water. A large expedition here in 1984 was the forerunner for the aforementioned 1994 expedition.

During the 1984 Expedition top cave divers, including the late Rob Parker, spent 4 months in the field exploring the Cueva de la Pena Colorada. Ultimately it was the logistical pyramid required to move diving cylinders to the final sump which brought the expedition to an end. This experience prompted Dr. Bill Stone to develop the CIS lunar rebreather, but it was 10 years until it was ready for use in the 1994 expedition. 

Exploration in Sistema Huautla is steeped in history. The development of new techniques and equipment for this cave has paved the way for modern exploration. At the same time we will literally be treading in the footsteps of previous great cave explorers. 

The location of Sistema Huautla in the Mexican state of Oaxaca.