12/25/21: PEP Trip Report - An Untraditional Christmas in Sistema Purificación

Updated: Mar 24

By Ethan Perrine

Christmas morning in the Canrado Castillo field house found a team of cavers pouring over maps at Gill’s dining table. I entered and crossed the room toward the high shelf where my animal crackers were hidden. Breakfast in hand, I sat down to join the fold. Bev Shade was studying the maps for Oyamel and Allarines, while Matt Olifant and Nancy Pistole flipped through survey notes of Valhalla, a section of Sistema Purificación near the field house. I had been there a few days earlier and agreed to guide Matt and Nancy to the first marked station after which I agreed to join Mowgli for the day’s primary objective. We scattered to pack snacks and I met Matt and Nancy to begin our hike through the village. A brisk ten minute walk later I was squirmuing through the narrow boulder entrance, using my body to check for snakes. Soon the three of us were off and moving. I soon realized that I had condensed the route in my head...considerably. If you’re wondering if I am referring to the route to the cave, or the route in the cave, that’s correct. I had told Bev I’d be back in 20 minutes which we’d already spent on the walk there. So, I ushered them further and further, twist after turn after squeeze after climb, and occasionally rounded the corner to dart ahead and covertly confirm that I was not leading us astray. Finally, I saw a familiar station that I had set days prior and bid them adieu after agreeing on a callout time.

I tore back to the entrance as fast as I could and got out at 11:14. I sprinted back to the field house where I was relieved to find Bev still showing route information to Mowgli for our day’s objective. We were going to rig Oyamel through the Lower Pit Entrance, all the way down to -82m at the Slit Pit. Simultaneously, Bev and Sean were going into Allarines to bust through a dig constriction at the bottom. They intended to come out through Oyamel, and we were meant to be waiting for them. This would add Allarines to the extent of Sistema Purificación, which Oyamel already connects to. As we stood over the map, I took note of all the blue water drawn in nearly every passage. I am sensitive to the cold and wasn’t bringing my wetsuit so I wondered to myself if I would get wet that day. Mowgli and I set off for the cave, which was just a short short walk from the field house in the opposite direction of Valhalla.

We remarked on how pleasant the path was and chatted while we meandered along the GPS route. Upon reaching the supposed coordinates at the base of a towering limestone henge, we struggled to find any signs of a cave entrance. We scoured the area inside, around, and above the henge and after a hunt that left us with GPS track resembling spaghetti, found a sink with a pit and decided that we were probably in the right spot. We stood overlooking a 20-25 foot deep drop, shaded by two sturdy oaks. I rigged to a branch and Mowgli went down to find out if there was passage at the bottom and if so, if it matched the map. He whooped in the affirmative and soon we were both at the bottom facing a duck under.


Mowgli is a caver of many skills, but he said way finding was one he needed to work on, so I followed his lead. Even if I had been leading the way, none of my map reading experience had prepared me for the multi level Gordion knot of a cave that we were examing on his phone screen. The beginning of the cave was simple though, and confirmed that we were in the right entrance of the correct cave. We knew this because just inside the entrance room was a still, blue pool of water. I got the feeling that I may be getting an answer to my question about staying dry sooner rather than later. Mowgli lead the way and we carefully traversed along an archipelago of rocks that sat above the water line. We made it across with relative ease and I hoped out loud that all of the pools would be traversable.


Moving further in, my inner monologue was interrupted as I came face to face with a worm-shaped, transparent blob. It was attached to dripping flow stone on the wall and scanning around I could see several more. The blobs appeared to be a cocoon; within each one was a larva that freely floated in the iridescent goo medium. These were totally new to me, so I documented them and pulled myself away to catch up with Mowgli. He was beginning to climb around a waist deep plunge pool. Traversing successfully look grim and after a few moves Mowgli fell in. He made peace with it and waded to the other side. I on the other hand, was determined. I floated my pack and rope to the pool’s far side, and climbed along the slick holds protruding from the ceiling. As I crossed the halfway mark, the holds were smaller, fewer and farther between. I spanned the wall with my arms and was straining, hard. My trembling fingers slipped off the slick stone as I surrendered and slid in. My boots flooded, my pants soaked up to the thighs, and with them went my hopes of staying dry. I wrung out my socks in the next dry room and we checked the map. The drawn passages were spot on as we looked around and we were growing more confident with our navigation.

On the floor, much to Mowgli’s dismay, I spotted more intriguing fauna. Yellow and black Xystodesmid millipedes hidden in flood debris on the floor. I documented them too, again falling behind Mowgli as he pushed on. We regrouped and pushed on.