Snowy River passage in Fort Stanton Cave—scientific sample collection and exploration

The other weekend, May 18-20, I did a 3 day camp trip in Fort Stanton Cave, just 3 hours away from Albuquerque. I went with some Massachusetts caving friends who were in the area because they come to Fort Stanton for caving once or twice a year: Riley Drake, John Dunham, and Ramon Armen (much credit to them for many of the photos in this trip report!). We camped at Midnight Junction, which is an established camp in the cave in the Snowy River passage, 10.2 miles of underground travel from the entrance. Fort Stanton Cave is notable for having passage that is extremely remote from the entrance in terms of distance and travel time. While other caves are longer in that they have more total passage, those longer caves tend to have densely connected passage that doesn't get too far from an entrance. The furthest point from the entrance in Fort Stanton is a whopping 13 miles of underground travel from the cave entrance.

When you're all the way back there, you are extremely isolated from anything and anyone on the surface of the Earth. You have no communication with the outside world, and no tools or other amenities of modern civilization other than what you and your team carried in there. If someone gets hurt or something goes wrong in any way, expect a a full day before anyone on the surface knows about it (via some of your team members taking off for the surface to tell them in person), and 2 days before any supplies or people they send to help arrive at you. This sense of extreme remoteness and disconnect from the outside world, altho sometimes scary, is one of the major appeals of caving for me.

The Snowy River Passage in Fort Stanton Cave is notable not only for going extremely far from the entrance (it goes from ~1 mile from the entrance all the way to ~12 miles from the entrance), but also for having a beautiful white calcite crystal formation covering the floor uninterrupted for the entire 11+ mile length of the passage. This formation is extremely unique, with nothing like it of the same scale anywhere else in the world. The Snowy River formation is the world's longest single cave formation, and the furthest reach of the cave out at the current known limit of exploration of Snowy River is by far the most distant one can get from a cave entrance underground, in terms of both in-cave travel distance (13 miles at a side passage off of Snowy River) and straight-line distance.

John in some nice Snowy River Passage. It goes on forever and ever, and is still being explored!

More classic Snowy River Passage. Easy walking.

John walking on Snowy River. If only it were all this easy.

A map of Fort Stanton Cave, with several locations labeled that I will refer to in this trip report. Click the map for a full-sized version.

Besides the challenge provided by the extremely long and remote nature of the far Snowy River trips, there is also a challenge associated with conservation of Snowy River. Snowy is a clean, beautiful white cave formation surrounded by muddy and otherwise dirty passages. Carelessly travelling on Snowy and adjacent dirty passages would track dirt all over it and ruin its pristine, pearly white appearance. Anyone who travels on Snowy River has to take great care to avoid getting Snowy dirty. This involves changing between clean and dirty clothes multiple times per trip when switching to travelling on Snowy to travelling on dirty passage for extended periods of time, and putting on clean or dirty shoe covers when briefly switching between Snowy and dirty passage. We also only travel on Snowy River when it is dry, without any pooled or flowing water in areas where we have to walk or crawl, because Snowy River gets soft and malleable when wet and could get permanent footprints if we travelled on it in that state. Snowy River floods irregularly and takes months to dry up after it floods, so conditions when it is dry all the way out to its current known furthest point are cherished opportunities to travel to the frontier. This spring there has been an unexpected and welcome period of dry conditions on Snowy, and I am thankful to have been invited on a far Snowy River trip during these conditions.

A pool in Snowy River that we unexpectedly encountered the previous time I was here. We were able to walk around this one without stepping on any wet parts of Snowy, but shortly after we encountered impassable water.

The furthest known reaches of the cave are still full of unexplored passages that keep going off into the unknown. We were going to travel to those far reaches at the limit of exploraiton. We had 2 goals on this trip:

1. Collect some samples for scientific analysis. My friend Riley Drake, a biology PhD student at Emory University, studies cave life (among other things). She was interested in studying the water in various pools in the far end of the cave, where very few humans have ever been. In fact, one of the pools we were to sample water from, had only ever been visited by the original team that explored the section of passage the pool is in and found the pool; that's 4 humans ever. We would be the second ever group of humans to visit this place and would collect water from it while it was still highly unimpacted by humans.

   Riley also wanted to collect samples of small snail shells that previous explorers had found in a dry streambed in a passage very close to Midnight Junction. She wanted to determine when these snail shells were washed in to the cave, and what species they are (if they even are any extant species).

2. Exploration of new passage. We had a long list of leads (unexplored passages in the cave) near Midnight Junction Camp. After we collected all the samples we wanted to, we were to pick whichever leads looked interesting to us and start surveying them.

I got to the Fort Stanton field house where Riley, John and Ramon were at around 8:30pm on Friday May 17th, the night before we were supposed to enter the cave early Saturday morning. The others had arrived there less than an hour before. We quickly packed all of our bags, double checking to make sure we had everything given how rushed our packing was. I was done with packing and in my sleeping bag by midnight. We all got up at 7am, wishing we had a little more sleep but still excited to get in the cave. I choked down my massive breakfast that was a whole box of mac and cheese, and we all got in the cave at 8:30am.

There is about a mile of travel through the "historic" section of the cave (known for hundreds of years, including to some Native Americans who explored parts of the cave near the entrance using cane torches) before one gets to Snowy River. Much of this is huge walking borehole, and it takes about 45 minutes normally. However, a section of this huge walking borehole called Conrad's Branch was flooded with calf-deep water, which slowed us significantly. The water was murky with low visibility and the floor under the water was sloppy mud. Falling in the water would mean that all of our gear, including our clean gear for Snowy River, would get soaked with brown muddy water and be way too dirty to clean up in a reasonable amount of time, which would mean we would quite literally have to turn around and can the trip. To make sure that there was no chance we would fall in the water, we all brought a ski pole to use as an extra point of contact when travelling through the deep water. We also brought a separate pair of dirty-mode pants, rain boots, and socks for travel through the flooded area, in addition to our standard dirty-mode clothes, as these clothes got way too wet and muddy to bring with us on Snowy River, even packed away in bag after we changed into clean clothes. The water was just deep enough to flood our rainboots (slightly below knee-deep), so we all did this section of cave with wet feet.

Conrad's Branch, near the entrance in the historic section of Fort Stanton, with deep water. It is unusual for this passage to have water, especially when Snowy River is dry all the way out to its current known end.

We got on Snowy River at Turtle Junction, after a little over an hour of travel from the entrance. Much of Snowy River is large, pleasant, easy walking passage. However, there are still plenty obstacles that slow you down. Occasionally the ceiling in Snowy River passage does get low and you have to crawl on it. Whenever you travel on Snowy River, but especially when you crawl on it with the ceiling/walls very close to you, you have to avoid touching the ceiling and walls with you or your pack. This is because the ceiling and walls are often covered in dirt and other sediment that will fall off and get Snowy River dirty if you so much as slightly brush against them. Whenever you travel on Snowy River you carry a bag with damp clean rags with you, so you can clean up any messes you do make. You may have to clean up Snowy River itself or your clothes/skin/pack so you don't transfer dirt from yourself to Snowy River. Minor accidents that spill a little bit of dirt are not a big deal as long as you immediately notice when they happen so you can stop and clean them up right then and there. But stopping to clean up yourself and/or Snowy does slow your entire team down, so everyone does try very hard to avoid touching anything other than Snowy. It's the reverse of that childhood game "the floor is lava"—in this case, the floor is safe, and everything else (walls, ceiling, breakdown blocks in the passage) is lava.

Riley about to start a crawling section of Snowy River. Make sure not to touch any of the dirty walls or ceiling or else you'll have to stop and clean up your mess in the middle of the crawl!

There used to be a section of Snowy River that was a long section of crawling called the Crawl from Hell. But it was bypassed via a passage called the Black Rock Bypass. The Black Rock Bypass is a dirty-mode passage that takes about 45 minutes and is not exactly easy (it's full of stoopwalking, crawling, and various other obstacles) but still saves a ton of effort over the worse crawling section, that includes low belly crawling, on Snowy River at that section.

You see fun and interesting patterns like this when large rocks fall into and get embedded in the Snowy River formation. I like to call these "gift-wrapped" rocks.

Sometimes the ceiling directly above the Snowy River formation can be really low, crawling height or even impassable, but the passage itself is taller off to the side of Snowy. Then it makes sense to walk off to the side of Snowy on the dirt banks. In order to not track dirt from the banks onto Snowy, we put plastic tarps over these dirty sections so you can stay in clean mode while stepping off of Snowy onto the dirt-floored parts of the passage with taller ceilings. We call these plastic tarps "magic carpets". The magic carpets can save a lot of time and effort, but sometimes they get annoying when not placed well or when they get dirty. My first and only other Snowy River trip, last October, was a magic carpet maintenance trip, where we improved the route by working on some of the worse tarps. This included staking down tarps that were on slopes and thus liable to shifting around when people walk on them, moving tarps further away from obstacles so you don't have do tiptoe around obstacles when walking on the narrow tarps, adding more tarps where they were useful but hadn't been placed on previous exploraiton trips, and cleaning tarps that had gotten dirty. That trip was very satisfying because the trip out of the cave was noticeably easier afer we improved the tarp situation on the way in.

A good tarp, that lets you walk where there is a much taller ceiling to the side of Snowy, away from obstacles.

A not-so-good tarp, that puts you uncomfortably close to some obstacles. Altho it's not clear that the tarp could be made any better, since the dirt slope gets steeper the further away you get from the obstacles.

Riley, Ramon and I in some Snowy River passage with a classic black manganese oxide coating all over the ceiling. This black layer is common throughout Snowy, and provides a beautiful contrast between the jet black mangenese and pearly white Snowy. However, it can be annoying because it very easily flakes off and crumbles onto Snowy if you slightly brush against it. You have to take extra care around the black manganese coatings to not bump into them.

Sometimes you have to get off Snowy River onto dirty surfaces where you can't use tarps for various reasons, such as the dirty surface being uneven and rocky, or too long to carry that length tarp out there. Then you use shoe covers to keep your clean shoes off the dirt. Putting on and taking off shoe covers is an intricate dance in and of itself: you have to balance on one foot with your heavy pack, often on an uneven surface, stick out your foot over a dirty surface so you don't drop dirt from the dirty shoe covers onto Snowy, put the shoe cover over your shoe at the end of your outstretched leg, then step onto a dirty surface, all without touching anything dirty like a wall for balance. This dance gets quite tedious when you do it hundreds of times during a single trip, and it can be somewhat high-consequence as a slip and fall onto a dirty area could spill quite a bit of dirt onto Snowy which you would have to clean up.

One of the more extensive shoe-cover obstacles is Mount Airy. Mount Airy is a breakdown pile atop Snowy River about a third of the way (in terms of travel time) to Midnight Junction. You gain maybe 100 ft of elevation by scrambling over breakdown for a few hundred ft. The standard procedure is to put shoe covers on and take your gloves off so you can touch the dirty breakdown with your hands without getting your clean gloves dirty. Scrambling around breakdown in shoe covers, while making sure not to touch anything with your knees elbows, or other body parts, is certainly a unique challenge that I haven't experienced in any other adventures.

After Mount Airy is a section of Snowy called the Eggshell Trail, because here Snowy gets very thin and easily cracked. We travel very slowly thru this section, all walking single file in the same spot so we contain any impact we make to one spot. By carefully stepping on the spots that look thickest, you can generally avoid cracking Snowy, but it requires soft steps and careful attention to where you place your feet.

The Eggshell Trail section of Snowy River, with thin cracked parts of Snowy clearly visible. The edge of Snowy, where I'm standing, tends to be the most solid in this section.

Our first chance to collect water for drinking in the cave was at Finger Lakes, which is a series of pools on Snowy River about 2/3 of the way to Midnight Junction by travel time. Riley wanted to collect some water samples for analysis before we collected drinking water which would possibly contaminate the pools. This was the first scientific sample collection stop of many on the trip.

Riley carefully crossing Finger Lakes (on the way out, on the last day of the trip). Glove off for the hand that is touching dirty rock.

Immediately after Finger Lakes is Rough Country, a section of breakdown-filled borehole not too unlike the Mount Airy breakdown pile, except much longer (~1 hour of travel) and with some fairly exposed, high-consequence climbing above tall dirt/rock cliffs in the breakdown. Rough Country is also far too long and difficult to do in shoe covers to keep your shoes clean, unlike Mount Airy. Instead our clean/dirty strategy was to switch our bottom halves (shoes, pants, kneepsds) to dirty clothes, while keeping our shirts and our packs in clean mode. We couldn't switch our packs to dirty mode as we left our dirty over-packs at the Black Rock Bypass, the last extended section of dirty-mode travel before camp. We didn't get any pictures of this section, as we were all focused on not falling off the numerous cliffs in the breakdown and on not getting our upper halves dirty.

Rough Country, despite being full of obstacles and a lot of work, is a very complex, interesting area with many leads. In several spots you can see the Snowy River formation at the bottom of the passage off to the side, altho the main travel route stays high and off Snowy for the entire length of the breakdown passage. The passage is huge, even bigger than most of the big parts of Snowy River, and the uneven breakdown floors often make it hard to see the entire passage. It can be hard to tell what is a real lead going off in another direction versus what is just another way thru the breakdown in the same passage. On this trip in general, but especially in this passage, I got in the habit of pestering John (who knows the cave very well) every time I saw another passage "is that a lead?", "does it go?", "does it still go?". Quite often the answer to all those questions was "yes".

After about an hour we were through the Rough Country breakdown and back on Snowy River. From here to Midnight Junction is fairly straightforward Snowy River travel, although there are very few magic carpets out this far as exploration teams stopped wanting to bring them out this far on their long survey trips. This meant tons of putting on and taking off shoe covers to cross dirty sections in the Snowy River passage. I lost count of how many times we had to swap into and out of shoe covers between Rough Country and Midnight Junction—probably around 50? I was pleasantly surprised that no one on the trip ever lost their balance and fell during the hundreds to one-legged balancing acts that are putting on and taking off shoe covers while standing on uneven ground and wearing a heavy pack.

Riley in a nicely decorated section of Snowy River. SRS437.

We finally made it to Midnight Junction at at 9:30pm, 13 hours after we entered the cave. This was a bit longer than the 11 hours or so I had been told to expect to get to Midnight Junction. At Midnight Junction, the passage splits. The right passage is the continuation of Snowy River, and the camp (which has much gear including sleeping bags and a stove permanently stashed there) is in this passage just past the junction itself, on a flat mud bank just above Snowy. The left passage takes you to Harmony Hall after a few minutes, which is an intersection where you gain Midnight Creek, a stream passage that goes both ways and is the water source for camp.

Altho Midnight Junction is supposed to be a nice camp, I actually wasn't a huge fan of it. It is flat, with a soft dirt floor, and warm, which is nice. But my objection about the camp is that you are somewhat in tarp jail when you're there—the tarps are clean and you have to be in clean mode when you're on them, but the dirt bank around you is dirty. To leave your tarp you have to put on shoe covers, and even then you can't sit down on the dirt; you have to be in full dirty mode to do that. The tarps are not huge at about 5 by 10 ft, and all of your stuff that you unpack onto the tarp takes up a good amount of space. I felt a little trapped on my small tarp, unable to get off it and hang out around camp without changing into dirty mode. Still, it worked well enough for camping and I slept well there on the soft flat dirt. At least it wasn't a hammock camp.

The 4 tarps that make up Midnight Junction Camp. Snowy River is on the left. You can see that your stuff on the tarp takes up a significant amount of your meager space.

We quickly unpacked our gear on the tarps, made some dinner (which for me was my version of dinner mix, loosely modelled after the Cueva Cheve dinner mix they use for long underground camp trips), and switched into dirty caving mode. It was time to collect water then begin our second science sample collection mission: collecting snail shells that had been washed into the cave near camp. From Midnight Junction we took the left passage, which quickly brings you to the Harmony Hall intersection where Midnight Creek is. Before we collected drinking water there, Riley collected a water sample from Midnight Creek. We then went right (downstream) into a passage called La Culebra. where the snails were.

Riley collecting a water sample from Midnight Creek at Harmony Hall. Many pretty soda straws/small stalactites in the ceiling. This is looking upstream/left from the Harmony Hall intersection.

We went slowly down La Culebra, scanning the passage for snail shells. We found several spots where several snail shells were lying on the floor, often right in a pile of charcoal too. Probably some event that washed in some charcoal also washed in these snail shells. I wonder how related the charcoal and snails are—maybe some large fire event that made a bunch of charcoal on the surface also killed a bunch of snails, all of which were washed in together? Identifying and dating the shells should help answer this question. Another interesting observation we made in this passage is that in multiple spots, the footpath thru the dirt had been visibly washed away where the footpath crossed a low dry water channel in the dirt floor of La Culebra. So La Culebra must have had flowing water some time in the past few years. That's a nice data point to have, as it's not obvious that this passage takes water anymore. Midnight Creek drains away from the passage right after the Harmony Hall intersection, and there was previously no indication that the passage ever takes water from anywhere else.

One of the snail shells we found and collected. Ruler for scale. I can't wait to find out how old it is!

More snail shells, these ones in piles of black charcoal, sitting on the floor of La Culebra.

Riley collecting snail shells in the floor of La Culebra.

Another interesting find in La Culebra: a calcified caterpillar (?).

After collecting several samples, we turned around and made it back to camp at 1:20am. When I cave camp, I like to get on what I call "cave time", which is when you do long days of exploration that result in you getting back to camp very late, then sleeping for 9 or more hours after that no matter what time that results in you getting up the next morning (or afternoon). This means that your "days" become longer than 24 hours, often 30 or more. I find that irregular schedules like this work really well for me when cave camping, because really long days get me nice and tired which helps me fall asleep easily, and because the lack of daylight and irregular noises from surface weather means I sleep really well even when I'm off my usual 24 hour schedule. However, the rest of the team said they do not work with that schedule, and that they would be up early the next morning according to their internal 24 hour clocks no matter what time we all went to bed. Oh well, no "cave time" for me.

We woke up at 8:30am the next day (thankfully not too early) and set off for Laguna Lechosa, a large pool at the current known furthest reach of the cave. We were out of camp at around 9:50am, in dirty mode at this point. From Midnight Junction, the route to the end of Snowy River actually follows a different passage than Snowy for a while before getting back on it at 4:30am junction (yes, named for the time of day when it was first discovered). The route goes to Midnight Creek, the water source just outside of Midnight Junction camp, then turns right and follows La Culebra (which transitions from merely pleasant walking passage into huge borehole) for a while. After following the impressive La Culebra borehole for a while, there is a mildly confusing area with a few turns. The route first brings you thru an amazing section of velvet flowstone ("Red Velvet Passage") that requires clean shoe covers to keep it clean. After another intersection, the passage abruptly changes to an annoying low belly crawl with grabby cobbles on the floor and many stalactites sticking down from the ceiling that you must avoid breaking ("Catch 23"). The belly crawl is high-effort but short, and quickly open up into walking passage that brings you to 4:30am junction where we finally regained Snowy River. The original route to this area followed Snowy River all the way from Midnight Junction, but apparently Snowy gets very thin and fragile there, and the team that explored that route recommended that it not be used again.

The amazing Red Velvet Passage. Shoe covers on.

The Red Velvet passage abruptly brings you to Catch 23, an annoying but short belly crawl with grabby cobbles in the floor and delicate stalactites in the ceiling you must avoid.

Along the way there was one handline downclimb, perhaps 15 ft, over a dirt cliff. The handline was anchored to 2 rocks which were embedded in a not very secure space in between the dirt floor and a bedrock protrusion in the ceiling. As the first person went down the handline I noticed that the anchor for the handline shifted a bit, and I immediately jumped onto it to secure it by pushing my shoulder into it. After the first person went down safely, we tried to move the rocks into a more secure position, but we didn't have much to work with. We decided that everyone else would climb down using the handline, with me backing it up by lieing right next to it, ready to push my shoulder into the rocks to hold them in place in case they shifted more. But I wouldn't actively push myself into the rocks otherwise, so they could be tested so the last person down (myself) could go down without a backup, having tested the anchor.

Riley climbing down the dirt cliff using the handline, while I back up the marginal anchor above.

Once we had regained Snowy River at 4:30am junction, we encountered pools in Snowy River with increasing frequency. Riley stopped at a few of them to collect samples. At this point we were caving in dirty mode, mostly on dirt banks to the side of Snowy, and frequently crossing it with shoe covers. It seems that more tarps would be very useful here if people travelled this section in clean mode, but given how often you are off Snowy in this section I'm not sure that bringing tarps and doing it in clean mode would increase efficiency at all. We crossed Snowy River at SRS772 and found it flowing with water—not just with a standing pool, but actual flowing water. This was the first time we had seen flowing water on Snowy this trip. Thankfully we were still able to cross it by hopping over some rocks which made a near-bridge over Snowy.

Shortly after crossing Snowy with flowing water, we arrived at a large breakdown room around SRS779. This breakdown room is confusing, with Snowy nowhere in sight, but many leads heading off in different directions at different levels. We needed to find Laguna Lechosa, a large pool that was the main target of Riley's science sample collection mission. We also wanted to find the route that regains Snowy River from this room, to check on it and see if it was flooded (as it was during the one and only previous trip to this place). After poking around in several different passages for an hour or so, we finally found the Laguna. Laguna Lechosa had only been visited by one other party of humans—the original exploration party that found and surveyed this area in 2022. The area is extremely isolated from, and unimpacted by, humans, and it is extremely interesting to ask what kind of life is in the water here. I look forward to hearing about her results and will share them here in the future.

While Riley was collecting her samples from Laguna Lechosa, I went down the passage from this room that regains Snowy River, to see if Snowy was wet. The passage went as a belly crawl for maybe 20 ft before dropping into a nice sized walking passage with Snowy River right there in the center of it. And Snowy was indeed flowing with water, as we expected. That doesn't bode well for the next trip—with the amount of water flowing (I estimate about 0.5 cubic feet per second). I can't imagine it will dry up in time for the scheduled exploration trip at the far end of the cave this June. Oh well, they'll have plenty of other leads in that area to explore instead.

Riley collecting her water samples at Laguna Lechosa.

After Riley finished collecting her samples and I was done checking on Snowy River, we headed back to camp to unpack the science gear and make dinner before switching to exploration/survey mode. At the first shoe cover crossing, Riley couldn't find her shoe covers, and she figured she had left them somewhere in that complex junction area near the current known furthest point in the cave. Riley and I went back to that area to look for them, which was thankfully only 5-10 minutes away at that point. While we were looking for the shoe covers (which we found at the Yellowstone River where we had last used them), John and Ramon surveyed a small side lead at SRS769 (marked on the survey as "2x6 gets low bad") that went as a crawl for a few stations before ending in a sump. After that we made it back to camp uneventfully, stopping in La Culebra several times to collect a few more snail samples that we didn't have time for the previous night.

We were back at the Midnight Junction camp at 6pm. At camp, we dumped the samples and science gear, made a quick dinner, and switched to exploration+survey mode. We were out of camp by 7pm on our way to survey some leads in the La Culebra Arriba passage (MJ121+) and MA passage. The route to these passages involved turning left at Midnight Creek (the stream where we get water a few minutes from Midnight Junction) instead of turning right towards La Culebra. We travalled for maybe 20 minutes upstream in Midnight Creek, which involved one short crawl where we had to take care to stay dry and clean(-ish, as we were in dirty mode at that point, but still didn't want to get our dirty clothes covered in slimy mud). Scramlbing up through a large hole in the wall/ceiling brings one to the intersection of La Culebra Arriba, a huge borehole that goes left from the intersection, and the MA survey, another huge borehole that goes right and is somehow unnamed despite being an extremely impressive borehole. This intersection was extremely impressive with ~60 ft tall boreholes going off in either direction.

Ramon in the massive La Culebra Arriba passage, at MJ123, near the intersection with the MA survey.

Ramon, Riley, and myself in the massive La Culebra Arriba passage, around MJ123.

The first lead we went to was in La Culebra Arriba (turning left at that intersection), at MJ133, marked as "10x10". On our way there we passed another lead at MJ124, marked "5x10", which we thought looked pretty good and would be a good option if our 10x10 lead didn't go very far. The lead was exactly as described, nice 10x10 walking passage. We tied in at MJ131 because we couldn't find MJ132 nor MJ133, and started surveying. John and Ramon sketched, while Riley set points and I was frontsight.

Ramon and I at the start of our survey at MJ131B.

The passage continued as nice walking passage with some beautiful velvet flowstone for 200 ft before reconnecting with La Culebra very close to midnight junction at MK4. Although we would have preferred that the passage continue forever with its large, decorated, pleasant character, it was useful to close a loop and provide a shortcut back to camp. This new route back to camp would bypass the wet crawl in Midnight Creek and result in perhaps 10 minutes less travel time back to Midnight Junction. This was MJ131A-E.

Riley flagging a trail thru a delicate section of passage while surveying, at MJ131C.

Riley at the end of our passage where it connected to La Culebra and made a nice shortcut back to camp, at MJ131E. She's looking down a 10-15 ft drop, although there's an easy downclimb on the left side of the pit.

Another side lead in this passage also connected to La Culebra after a few stations and had more beautiful velvet flowstone. This other side passage connected at a 14 ft overhanging pit that we couldn't downclimb. This was MJ131H-J.

Riley in the side passage that connected to La Culebra a second time, at MJ131H.

Nice velvet flowstone, in the side passage that connected to La Culebra a second time, at MJ131H+I.

Velvet cave pearls in the floor of the passage, also at MJ131H+I.

The 14 ft pit that connected to La Culebra a second time, at MJ131J.

After connecting to La Culebra in 2 different spots, we went back to the 5x10 lead further back in La Culebra Arriba, which started out as stoopwalking passage with some nice gypsum needles in the floor. This went for an even shorter distance before connecting to the intersection between the Midnight Creek Passage, La Culebra Arriba, and the MA passage, via a tortuous route through the breakdown in the floor of that intersection room. This was stations MJ124A-G.

The start of the 5x10 lead at MJ124.

Riley crawling into the breakdown at MJ124D, that would connect into the large intersection room at MJ123 thru the breakdown floor.

After killing those 2 leads there was some talk of going back to camp, but we decided we would rather continue surveying as there were more leads not too far down the MA passage and we all had plengty of energy. I'm glad we did, because the 3rd lead we surveyed ended up being quite interesting, and I got to see the MA passage which is more huge impressive borehole like La Culebra Arriba.

From the intersection, we now went right, down the MA passage, which was similarly impressive borehole that got 80 ft tall. The first leads were a pair of side passages on both sides of the borehole at MA3 (only 3 stations from the intersection). The lead on the left wall of the borehole was marked 3x3, and the lead on the right was marked 6x3. Naturally we chose the lead on the right and started surveying.

Me in the massive borehole that is the MA survey. I am at MA3, immediately before the lead we started surveying.

This lead started out as fairly nice walking passage, 3 ft wide and just a body length tall, and quickly got even nicer. It started averaging about 4 ft wide, and the ceiling slowly gained height as the passage went on. TThe passage was fairly flat with little inclination, as was the floor which was mostly soft flat dirt. Eventually the passage gained a classic keyhole cross-section as the ceiling got tall, around 25 ft. The passage took many right turns which made our shots short (often ~20 ft) and the survey somewhat slow, although we certainly didn't complain as we were surveying nice, pleasant, virgin walking passage that didn't seem to want to end and was heading towards a large blank area on the map. And with 2 fast sketchers (John and Ramon), the sketch was able to keep up with Riley and I setting points and taking shots. There were no side leads in this passage, just one obvious walking passage heading off the map.

We decided to name this passage the Porcupine Passage, after a cluster of thick gypsum needles embedded in a clump of mud at the entrance to the passage that I thought resembled a porcupine. All of us New England cavers love porcupines and encounter them often when caving in the winter, as they love to shelter in the warm caves in winter in New England.

The cluster of gypsum needles embedded in a clump of mud that I thought resembled a porcupine. This was the Porcupine Passage's namesake.

John sketching in the Porcupine Passage.

Me and Riley surveying in the Porcupine Passage, towards the end where it got even nicer with taller ceilings and a classic keyhole cross-section.

The Porcupine Passage was full of nice gypsum formations like needles, but one formation in particular stood out. We found a thin strand of gypsum wound in a perfect helix shape, like a spring. I had never seen a formation like that before. We flagged it so others will see it and avoid accidentally brushing up against the wall it's on and destroying it.

2 views of the gypsum spring we found in the Porcupine Passage. It's maybe 5 mm wide.

It was at this point that I realized that Fort Stanton Cave is much more than just the Snowy River Passage. The cave is over 44 miles long, and Snowy River is only 13 of those miles. Side passages off of Snowy River make up much of the rest of that mileage, and many of those "side" passages are extremely impressive and interesting passages in their own right, such as the huge boreholes of La Culebra Arriba and the MA survey. And those side passages are full of great leads. There is lots of exploration to do in Fort Stanton, and I am excited to be a part of it during the next several years I'll be in New Mexico.

Once we used up a whole alphabet of stations MA3A-Z, we decided that would be a good time to turn around and head back to camp. At that point we had just over 1000 ft of survey for the trip. We scooped 30 ft of passage from there to make sure it didn't immediately end, and saw the passage continue around the next corner into the unknown. We used our new shortcut that we surveyed earlier that evening to get back to camp nice and quick. MA3 was probably 25 minutes of liesurely travel from camp using the shortcut. We were back in camp around 2am that night. I snacked a bit then quickly went to bed, knowing that we had to get up early tomorrow for our long day of travel back to the entrance.

We got up bright and early (really, dark and early because it's always dark in the cave!) at 7:30am the next morning for our exit day. Packing our bags and organizing camp took a while, as it always does, and we set off from Midnight Junction towards the entrance at 9:15am. I was glad to be out of tarp jail and up and moving fast. I estimate that my pack was 40-50 pounds, even heavier than the way in. Usually when caving or backpacking, one's pack is lighter on the way out, but the Fort Stanton rule that cavers must carry out all pee and poop from Fort Stanton means that one's pack gets heavier as the trip goes on. Water you collect from the cave to drink gets turned into pee which must be carried out. Lightweight dehydrated food with no water weight gets turned into poop which has water in it. I carried out 5 liters of pee from my 3 day camp trip, which is 10 pounds. The Fort Stanton camp packs have hip belts on them, which I was glad to have. This is the only time I've ever wanted a hip belt on a cave pack due to the weight.

The trip out was uneventful. Once I got past the last stoopwalking obstacle in the historic section of the cave, I took my shirt off and did the final hour of caving shirtless. At 55F, the cave might not seem super hot, but the high humidity means you do get quite hot and sweaty when working hard, especially when wearing long sleeves and pants in dirty mode to keep your skin clean. It was nice to be no longer concerned about keeping my skin clean for Snowy River, and to cave with minimal clothing to heat me up.

The 4 of us in the historic section of the cave, almost at the entrance. I am caving shirtless due to the heat. The photo is pretty blurry, but we were focused on other things as we were gunning for the entrance after being in the cave for 3 days straight.

The historic section of the cave felt like it took forever, with the calf-deep water (usually not present) slowing things down significantly. This section is usually very straightforward walking or even running in huge borehole, but the murky, low-visibility water with sticky mud floors meant we had to go slow and use our ski poles for balance. We made it to the entrance at 9:50pm. It took us 12.5 hours to get to the entrance from Midnight Junction, a little faster than our 13 hours on the way in. Not bad considering our packs were heavier than on the way in.

After unpacking my bag and dumping all my gear at the field house for the others to deal with in the morning (thank you Riley John and Ramon for dealing with that!), I started my drive back to Albuquerque. It was shortly before midnight when I started the 3 hour drive. I considered spending the night and leaving early the next morning, but I did want to be back at UNM early for the NQI Quantum Algorithms Workshop that was happening starting 8am the next morning. In fact I originally declined to go on this trip because I wanted to be at the workshop on Monday, its first day, but John talked me into coming (thanks John!). So I figured I would start the drive that night while I still had some energy, and pull over and sleep in my car as soon as I got tired. As I started driving, I was still full of energy and excitement from the amazing trip I had, but the sleepiness started to kick in around the halfway mark, just outside of Socorro. There I pulled over onto a BLM road and napped in my car until 5am. Then I drove the rest of the way to UNM, not even stopping at home, to save time and because the physics building has showers where I could clean up and change for the conference. Thankfully the conference had plenty of free coffee to get me through that long day without much sleep.

Thanks to Riley, John, and Ramon for many of the photos, which are also courtesy of the Fort Stanton Cave Study Project, BLM, and USFS.