Peña Colorada 2018


Cueva de la Peña Colorada (Cave of the Colored Rock) is a remote multi-kilometer cave system comprised of dry and submerged cave passages residing deep in the subsurface world of the Sierra Mazateca, a mountainous region of limestone and dense rain forest in the Oaxaca providence of Mexico. For the last 50 years, cavers from around the world have come to the Sierra to explore the regions extensive caves with the guarantee of finding seemingly endless un-explored cave passage.

Cueva de la Peña Colorada lies at the bottom of the deep Santo Domingo Canyon and is believed to be connected to the nearby cave ‘Sistema Huaulta’ which is the deepest cave in the Western Hemisphere. Sump 9 in Sistema Huautla is around 6 kilometers away from the Cueva de la Peña Colorada, and it is thought that the water which is last seen in Sump 9 in Sistema Huautla intersects Sump 7 in the Cueva de la Peña Colorada, before re-emerging in the Huautla Resurgence in the remote Santo Domingo canyon.

Since it is thought (but not proven) that the Cueva de la Peña Colorada connects into the cave system between Sistema Huautla and it’s resurgence, the primary objective of the 2018 expedition was to continue the exploration of the submerged passage beyond sump 7 in Cueva de la Peña Colorada. The teams enduring aspirations set the stage for the push divers to discover un-explored dry passage beyond sump 7 or perform an extended range and deep technical dive towards Sump 9 in Sistema Huautla. The last expedition to Cueva de la Peña Colorada was in 1984. Under the leadership of Bill Stone, Over 200 participants including locals, the Mexican military, and teams of experienced cavers that were up for the task of diving and surveying this cave, mapped Cueva de la Peña Colorada to 7.8 kilometers with 1.4 kilometers underwater. A total of 7.8 kilometers of virgin territory leading into the plateau were surveyed, with 1.4 kilometers of this distance underwater. This was comprised of 7 sumps, the longest of which was 524 meters in length. The expedition established the first ever subterranean camp set beyond an underwater cave passage. The team stopped at a point 55 meters underwater beyond sump 7.

Now, 34 years after its initial exploration, a team of 25 caver divers returned to Sump 7 to continue the exploration.


A large quantity of equipment was driven down from Texas in two vehicles. This included more than 60 diving cylinders, several hundred kilos of lead, a compressor, tubs of sofnolime, 3 DPVs, rope and caving hardware, underground camping equipment and food supplies.  The expedition was based in the small village of Loma Grande, over an hour of driving down small dirt roads from the nearest town. The people here are Mazatec, a very traditional community which still speaks the Mazatec language. The area sees very few visitors and as a consequence the people here are often suspicious of outsiders.

Cave explorers are one of the few outside groups which visit the region and despite their best efforts misunderstandings are not uncommon. It’s hard for the local villages to understand that we would give up our free time and spend money just to visit a hole in the ground. This leads to odd rumors about cavers visiting to hunt for gold, buy land or even steal children! Our own expedition became the source of some controversy in the village, and we were thankful to have a native Mexican caver with us who spent many hours reassuring the villagers that our intentions were honest.

From Loma Grande it’s an 850m descent to the Canyon floor and then a 40 minute hike up the canyon to the cave entrance.

Caving and Diving

The team’s goal was to place a series of divers in the final sump, Sump VII. To achieve this, the team had cover four diving sections and establish two underground camps. The sumps that required traversing were 2, 3, 4 and 5, all separated by sections of dry passage. Sump 2 is 14m long with a max depth of 4m; visibility would vary between 10m+ and 1m depending on the amount of travel seen; though it would return after a 12 hour period. Sump 3 was 180m with a max depth of 20m. It was a steady descent to 20m over 120-130m, then steep ascent. Typically visibility of around 4-5m, which would take a long time to recover.

Half an hour from sump 3 a lagoon is reached which during the start of the expedition was sumped. After the lagoon Camp 1 was established. A further two hours of caving allowed us to reach sumps 4 and 5. Sump 4 is ~55m in length, max depth 11m boulder floor, followed shortly by sump 5 approx a 130m dive at around 5m with a max depth of 10m. A hour of steeply ascending caving with several pitches then allowed us to reach camp 2. Here hammocks were used so that a team of 4 could sleep suspended over the rocky floor. From camp 2 it was only a short distance to sump 7. This sump is at the base of a 70m pitch and the steep walls offered no kitting up location so a ‘porta-ledge’ was carried into the cave and bolted to the wall at the bottom of the shaft.

All sumps required re-lining and all pitches were re-bolted. Completing these tasks as well as transporting this equipment, personal diving kit, underground camping kit and the large capacity cylinders required for sump 7 took many weeks. Finally after three weeks in field we were ready for the first push on sump 7.

Sump 7 Exploration

During a 9 night stay in the cave Chris Jewell and Connor Roe made two dives in sump 7 supported by Josh Bratchley and Gareth Davies With visibility around 5m it should have been easy to navigate but the scale of the underwater cave still meant their lights often failed to reach the walls. After picking their way through a boulder choke they descended to 33m and entered a large horizontal passage which matched the description of the previous explorers.

Following this passage steadily down they noted several alternative passages but instinctively headed deeper along the largest tunnel. At the lip of a small pot they peered down into the depths before descending to a rock and gravel floor at 51.5m depth. A little further ahead however the large passage stopped abruptly in a pile of well consolidated boulders jammed against each other. Retracing their steps whilst decompressing they scoured the walls for the missing way on but nothing could be found except the previously noted side passages which they decided to leave for the next day.

They conducted a second dive the following day to inspect the side passages they’d not entered previously. They explored a shallower section of the underwater cave which appeared to promise it might regain the surface but at 6m depth were again blocked by an underwater collapse. After the first team exited the cave the next team with Zeb Lilly and Andreas Klocher as exploration divers took up residence at camp 2. Over two further dives they confirmed the findings of Chris and Connor and completed the
survey work.


Unfortunately, there was no going passage beyond sump 7 and the water flow appeared to be static. This might mean that the water enters the cave from another location to relieve flowing water pressure from Sistema Huautla. It is without indecision that Cueva de la Peña Colorada Floods substantially after a period of rainfall but where is the water coming from? The Huautla Resurgence Cave discharges incredible amounts of water and the signs are apparent that Cueva de la Peña Colorada follows suit to the hydrology of Sistema Huautla.

Text: Chris Jewell
Photos: Chris Jewell & Michael Waterworth

Download: Summary Expedition Report


Website Use

Terms of Use

Please read these terms of use carefully before you start to use the site. By using our site, you indicate that you accept these terms of use and that you agree to abide by them. If you do not agree to these terms of use, please refrain from using our site.

Reliance of Information & Disclaimer

The materials contained on our site are provided for general information purposes only and do not claim to be or constitute legal or other professional advice and shall not be relied upon as such.

We do not accept any responsibility for any loss which may arise from accessing or reliance on the information on this site and to the fullest extent permitted by English law, we exclude all liability for loss or damages direct or indirect arising from use of this site.

Information About Us

The Ghar Parau Foundation is a 100% voluntary-based charity that manages an investment fund to provide grant aid to assist British caving expeditions to all parts of the world. The fund focuses on those expeditions which include an element of innovative exploration or scientific study. We are also particularly keen to encourage young cavers into expedition caving (as well as sport caving) to maintain an active caving community in years to come.

The Ghar Parau Foundation, a sub-charity of the British Cave Research Association, (267828-1) works by investing the capital within the fund and distributing the interest in the form of grants to caving expeditions who apply and fit the foundations criteria.

Accessing Our Site

Access to our site is permitted on a temporary basis, and we reserve the right to withdraw or amend the service we provide on our site without notice (see below). We will not be liable if for any reason our site is unavailable at any time or for any period.

Intellectual Property Rights

You may print off copies, and may download extracts, of any page(s) from our site for your personal reference and you may draw the attention of others within your organisation to material posted on our site. Please credit The GPF as the source and any expedition whose detail or report you have downloaded. Expeditions and organisations may have additional copyright or restrictions as to using their data and reports and The GPF does not relieve you from any of those additional restrictions.

You must not modify the paper or digital copies of any materials you have printed off or downloaded in any way, and you must not use any illustrations, photographs, video or audio sequences or any graphics without further permission.

Our status (and that of any identified contributors) as the authors of material on our site must always be acknowledged. You must not use any part of the materials on our site for commercial purposes without obtaining permission from GPF.

Our Site Changes Regularly

We aim to update our site regularly, and may change the content at any time. If the need arises, we may suspend access to our site, or close it indefinitely. Any of the material on our site may be out of date at any given time, and we are under no obligation to update such material.

Our Liability

The material displayed on our site is provided without any guarantees, conditions or warranties as to its accuracy. To the extent permitted by law, we, and third parties connected to us hereby expressly exclude:

This does not affect our liability for death or personal injury arising from our negligence, nor our liability for fraudulent misrepresentation or misrepresentation as to a fundamental matter, nor any other liability which cannot be excluded or limited under applicable law.

Information About You and Your Visits To Our Site

We process information about you in accordance with our privacy policy. By using our site, you consent to such processing and you warrant that all data provided by you is accurate.

Viruses, Hacking & Other Offences

You must not misuse our site by knowingly introducing viruses, trojans, worms, logic bombs or other material which is malicious or technologically harmful. You must not attempt to gain unauthorised access to our site, the server on which our site is stored or any server, computer or database connected to our site. You must not attack our site via a denial-of-service attack or a distributed denial-of service attack.

By breaching this provision, you would commit a criminal offence under the Computer Misuse Act 1990. We will report any such breach to the relevant law enforcement authorities and we will co-operate with those authorities by disclosing your identity to them. In the event of such a breach, your right to use our site will cease immediately.

We will not be liable for any loss or damage caused by a distributed denial-of-service attack, viruses or other technologically harmful material that may infect your computer equipment, computer programs, data or other proprietary material due to your use of our site or to your downloading of any material posted on it, or on any website linked to it.

Links from Our Site

Where our site contains links to other sites and resources provided by third parties, these links are provided for your information only. We have no control over the contents of those sites or resources, and accept no responsibility for them or for any loss or damage that may arise from your use of them. When accessing a site via our website we advise you check their terms of use and privacy policies to ensure compliance and determine how they may use your information.

Jurisdiction & Applicable Law

The English courts will have non-exclusive jurisdiction over any claim arising from, or related to, a visit to our site.

These terms of use and any dispute or claim arising out of or in connection with them or their subject matter or formation (including non-contractual disputes or claims) shall be governed by and construed in accordance with the law of England and Wales.


We may revise these terms of use at any time by amending this page. You are expected to check this page from time to time to take notice of any changes we made, as they are binding on you. Some of the provisions contained in these terms of use may also be superseded by provisions or notices published elsewhere on our site.

Your Concerns

If you have any concerns about material which appears on our site, please contact the committee. Thank you for visiting our site.


Privacy Policy

Your data

We do publish grants awards and expedition information and pass information to the press about the expeditions we support and grants we make. We do publish the names of expedition members but we do not pass on personal details to any organisation outside the British Cave Research Association or British Caving Association, unless requested to do under the Law of the United Kingdom.


Accessibility Policy

We endeavour to make our site as accessible as possible to people of all abilities. We test our site for compatibility with a range of browsers and permit those browsers to enable any accessibility preferences the user may choose to use. However, as volunteers, we cannot accept liability for any accessibility issues any user may have, though we shall be very willing to gain feedback and address any issues we can. Please use the site feedback facilities to do so. The GPF however, work strictly with the UK English language and, whilst this site should work, we do not design this website with features for use on mobile devices such as tablets and mobile phones.