7 March 2020 – Survey of DL4

7 March 2020

Dan Lamping
Tony Schmitt
Josh Hafner
Alex Litsch

Objective: Survey side passage found on previous trip. Experiment with drone in lower Thunder for checking high leads.

Alex, Josh, and I arrived onsite Friday evening around 9pm. We set up camp and rigged the hole to hopefully ward off the inevitable milling about on Saturday morning. It was a cold and windy night on the surface. I was thankful to have my camper.


Dan arrived Saturday morning around 9am. We were all at the bottom of the hole by 10:15am. This was Alex’s second trip into the cave, his first being a short trip during NSS convention in 2015.
We headed downstream to our lead. The last trip downstream, we checked a lead marked on our original survey notes. Turns out it was a walking lead just downstream of Horseshoe Falls at stream level. We vowed to return on a day trip to survey it. This was the return trip.


We pointed out various landmarks to Alex on the way to Jerry’s Cairn. We moved at normal pace and arrived at Jerry’s Cairn approximately 2 hours after leaving the bottom of the hole. Dan and I ditched our wetsuit tops at the Cairn. Dan showed Alex around camp at the cairn, noting that the rescue cache is still present. It is in a dry bag looped through a jug hole.

A low spot in downstream Thunder River.
A low spot in downstream Thunder River.


We continued on through the breakdown crawl to Horseshoe Falls. Just beyond the falls at stream level where the lead was, we dropped all of our gear. Against our normal protocol (survey as you go) we decided to go check out the lead and see how bad or good of day we were going to have. The passage starts out as walking about seven feet tall and six feet wide. Pretty quickly it shrunk to stoop walk with some hands and knees thrown in for good measure. The passage was muddy, but not as muddy as other places in Carroll. We kept going and soon noticed that we could hear a waterfall. It was odd because it was coming from ahead of us. This spurred us on. Soon we realized that we had to be coming back out into main passage near Horseshoe Falls. Sure enough, we popped out just on the upstream side of the falls. Many people have stood there over the years and not noticed the crawl taking off under the ledge.


We all had a good laugh about it. We then took main passage back to the beginning of the lead. We took a longish break and had hot meals and coffee. After break, we decided to let Josh work on the drone stuff in the big passage while the three of us (Alex, Dan, Tony) surveyed the passage. We found a tie-in with little trouble (D166A1). We surveyed the entire passage tying back in at D162 (labeled MF7 in the cave). Per normal Carroll naming conventions the passage would be DL4. It could be called “Horseshoe Falls loop” or “Horseshoe Falls Crawl” as this is a bit more descriptive. As we exited the crawl back into main passage at the top of Horseshoe Falls, we were greeted by the buzz of a drone flying overhead. I do believe that was a first for all three of us.

Alex Litsch and Tony Schmitt surveying in DL4.
Alex Litsch and Tony Schmitt surveying in DL4.


We ended up adding 250 feet of new survey. Josh in the meantime was working on flying his drone in the passage. Josh has spent considerable time and money building a purpose-built drone and training himself to fly without GPS. He has a pair of googles that he looks through and sees what the drone sees as he is flying. The test flights were a success. He was able to traverse several hundred feet of cave passage with the drone, even around corners from his location. He had a GoPro and still camera mounted to the drone. He checked a high lead in main and videoed it for us to see. Unfortunately, it doesn’t look like it goes, but there are plenty more to check. We ended up helping Josh try to get some video of the passage and a couple of still photos. Dan snapped a couple of still shots with the drone in action. Josh did not wreck or lose the drone and we came out with footage, so I would chalk it up as successful.
After the drone fun, we packed up and headed for the ladder. On the way out we checked a lead just downstream of the Little Lake Room, but before the Canopy Bell. I believe it to technically be DL2. We crawled back in a little ways. It was very soupy deep mud (the regular Carroll variety) it appears to be about a hundred feet long or so. A little dig at the end may yield more passage. DL2 is now on the short list for survey.

Josh Hafner flying his drone in Carroll Cave.
Josh Hafner flying his drone in Carroll Cave.


One interesting thing about DL2. Back in there was a little room. On the ledge about two feet off the ground were two bait sticks wired to a rock. The metal tags had numbers. One was 812, the other was partially illegible, but we could make out a 15. We couldn’t figure out how those would have got there. From what we know, Doctor Ashley never went downstream past Black Rock Riffles, so it’s a bit of a mystery.


After checking out DL2 we headed for the surface. I was the first to the ladder making good time. Soon the others joined. We exited the cave with the last man out around 9:30pm for a twelve hour trip.
Surface Stuff: the silo looked great, more organized and the trash is gone. Good job on whoever did that!


It was very windy this weekend. The wind break ended up being more of a “wind velocity accelerator”. Having a fire was almost impossible due to the vortex of wind coming around the metal. You couldn’t sit in there for very long without getting smoked out or wind chapped. Might have to consider changing that up a bit. As it was on this occasion it was more of a hindrance because we could not sit by the fire.


The road going in was no problem. We could tell it’s still new and a little soft in places but overall what an improvement!


Sunday morning we were able to visit with Jeff and Bill for a bit. We all agreed the gate at Mill Creek Road needs to be moved so you can pull off the road to open it.


We left Bill and Jeff right as the electrician showed up and we were off the property by 10:30 am.


While our footage gains have dwindled over the last few years, we are still plugging away at it. Who knows? Maybe one of the grim leads we have left will open up. You never know.


Submitted by Tony Schmitt March 2020

Drone flying in Carroll Cave.
Drone flying in Carroll Cave.

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