Sarlacc's Pit
Wells Gray Provincial Park, British Columbia, Canada
by
Lee Hollis et al.
The Team
Catherine Hickson, Lee Hollis, Ken Lancour (pilot), John Pollack and Chas Yonge.
Discovery
On September 9th, 2018 a significant new river sink was confirmed in Wells Gray Provincial Park. Earlier in April, on a flight through the remote northern parts of the park to conduct a Mountain Caribou census, Yellowhead Helicopters pilot Ken Lancour, and three government biologists including Bevan Ernst, spotted a very unusual feature. The caribou survey is performed annually by the BC Ministry of Environment and Climate Change, but this feature had never been observed before. The group spotted a very deep, partially snow filled pit that formed a prominent feature in the landscape. Lancour reported the feature to BC Parks who suggested he contact geologist Dr. Catherine Hickson. In turn, Dr. Hickson contacted colleagues John Pollack and Lee Hollis, and decided this was indeed a significant karst feature worth investigation. The cave had been dubbed “Sarlacc’s Pit” by the April discoverer group due do its similarity with the lair of Sarlacc, a creature from Star Wars.
First ever photograph taken from the helicopter during the mountain caribou census
All parties felt a short reconnaissance was essential, and planned a helicopter trip with the support and assistance of BC Park’s Tod Haughton. On Sept. 9th, Lancour, Hickson, Pollack, Hollis and Haughton used a Bell 206 Longranger to reach the remote site (Figure 1). Dr. Chas Yonge was slated on the trip but could not attend due to health issues. He was able to provide advice and context after the trip, instead.
Figure 1. Sept. 9th Royal Canadian Geographical Society recon team. L-R John Pollack, Ken Lancour (pilot), Dr. Catherine Hickson, Lee Hollis, Tod Haughton (BC Parks)
Exploration
The results of the ground reconnaissance exceeded expectations. The drainage containing the cave is 10.1 km2 in area, with a large stream that clearly becomes a significant river during peak runoff and glacier melt. The stream-bed is braided and often 20-22 m across, and a large and treeless avalanche slope rises approx 600 m above the cave entrance.
The entrance is not a sinkhole or a blocked feature, but rather a wide-open shaft 100 m across by 60 m wide, with an overhanging drop on the high side of 145 m (Figure 2). A sloping "line of sight" into the pit was roughly 180 m which may be an unprecedented shot length for Canada. The depth of the cave could not be measured from the surface with our reflectorless, laser Trupulse 360b due to mist from the entrance waterfall. We estimated the Sept. 9 flow at 0.5 cumecs (cubic metres per second) and the dimensions of the stream-bed suggest high flow run-off may exceed 10 cumecs.
Figure 2. Entrance shaft of Sarlacc's Pit with people circled.
Photo & Video: John Pollack
The overall horizontal distance between sink and resurgence is 2.1 km with a vertical drop of 460 m, and the resurgence shows evidence of two overflow passages above the active spring.
The Descent
After the initial flyover of the enormous pit, Hollis and Pollack assessed the most feasible access into the abyss. Given the unknown stability of the snow plug at the bottom, the decision was made not to do the most straightforward direct descent on the far wall but to abseil down the steep slope to the side of the pit.
Unfortunately Pollack was still recovering from Knee replacements so had to pass on this occasion meaning a solo descent, but supplied moral support from the surface by radio.
My rather heavy load of equipment included the following : 18v battery drill, 2 spare batteries and drill bits, hammer, 12 bolts, carabiners and wrench, crampons, 150m 10mm static rope, radio, camera plus all the other regular caving gear required to descend a 100m+ Pit and more importantly get out again !!
Initial belay was to a large boulder then a small but very sturdy tree giving the perfect takeoff over the edge. After about 10m of descent there was a nasty rope rub. It soon became apparent that the biggest issue of this chosen route of descent would be finding non frost shattered rock to install bolts . However I did pack the hammer for this reason and tapped and gardened away until suitable solid rock was unearthed placing approx 4 bolts on the entire 80m descent gardening all the way down to the snow plug.
Lee Hollis on the initial and to date (April 2023) the only descent of Sarlaccs Pit.
Photo: John Pollock
Following the waterfall route under the 3-5m thick snowplug wasn't particularly inviting so I chose instead to traverse through a small hole to the side placing another bolt before descending down to the fast flowing raging river. Due to the white water noise it was now impossible to check in with pollack on the surface.
It's worth noting that the weather was not favourable for the flight in as far as to say Lancour (our pilot) didn't think it was a good idea. Due to Hicksons now or never persuasion we did eventually take off and followed a worm hole through the cloud to get here and we had strict instructions that we had 2 hours on the ground (or under it) before departure. I took some rather haphazard video and photos then removed all non essential gear and tied it off on the rope before disconnecting from the rope and jumping across the river to a very wide rock shelf. The water had cut deep narrow fissures into the solid bedrock so it was relatively easy to cross, just don't fall in.
I then wandered along the wide ledge underneath the huge snow plug to the drip line at the far wall of the pit where the river tumbled into a huge dark abyss. Thinking I'll be back and given the time constraints this was my turnaround point. Making my way out the change in vantage / daylight angle exposed the massive snow plug was suspended only by a few touch points on each side making for a hasty retreat. You definitely would not want to be down here when this thing eventually collapses.
View under the suspended ice plug. Photo: Lee Hollis
An uneventful slog got me and the gear back to the surface with 5 mins to spare and fortunately the weather had changed on our favour allowing an extension to the return flight to observe more Karst features. What a great day it was and many thanks go out to the whole team. TBC !!!!
Geology
Meanwhile Hickson did preliminary geology at the entrance and determined the cave is an example of "stripe karst' formed in relatively thin (3-5 m) marble strata inter-bedded with garnet-mica schist. Pollack made a 3D photographically rendered survey of the entrance pit using both surveyed ground control points and 140 +/- photos taken from the helicopter with a Nikon D90. The images were later processed with Autodesk Recap software (Figure 3).
Figure 3. 3D photographic rendering survey of the shaft, side view.
Photo: Pollack 2019
Access
An announcement of the discovery was delayed while BC Parks organized First Nations consultation with regards to the name. When released via the Royal Canadian Geographical Society and the Canadian Geographic on-line, we were stunned when the story went global within days. Unfortunately several photos and Google Earth allowed the Reddit community to nail down the location in short order, and despite the remote location of the cave, BC Parks became concerned about liability / public safety. Hence on December 17 2018 the province instituted a recreational closure on both the drainage and the cave, with fines of up to $1,000,000 per day / 1 year imprisonment for violations were imposed. Simultaneously Hollis and Pollack filed a multi-year research permit application with BC Parks. Unfortunately this process dragged on for 4 painful years resulting in us withdrawing our application in October of 2022. We are currently assessing further options.
From 'Wells Gray Cave Frequently Asked Questions'
Order of the Regional Director, Province of British Columbia
Conclusions
This summarizes the back story on what we hope will be an emerging chapter in Canadian cave exploration. Of course any cave, even one with a huge shaft entrance, can shut down in a few meters. But the basics are here, an immense entrance shaft, the right geology, a 10.1km2 drainage area, and a very large run off . All suggests a big, dangerously wet, and challenging cave. What is truly surprising is such a large opening remained unknown for so long in a provincial park. Also consider there are other areas in the region with up to a km of depth potential, and known resurgences.
Lee Hollis, South Slocan, British Columbia, Canada. April 2023
Media Coverage
Canadian Geographic
Canadian team confirms presence of huge unexplored cave in British Columbia.
https://canadiangeographic.ca/articles/canadian-team-confirms-presence-of-huge-unexplored-cave-in-british-columbia/
Global News
Geologist Catherine Hickson describes cave discovery.
https://globalnews.ca/video/4721329/geologist-catherine-hickson-describes-cave-discovery/