Lidar imagery is so dangerously alluring. With the promise of seeing through vegetation to uncover subtle landscape features, it has been a gamechanger for many aspects of my research into faults and landslides...and an ever present distraction whenever new data is available for bush-covered karst areas. All of a sudden you can see pits, stream sinks, and resurgences that otherwise were completely hidden and know exactly where to look. It does not however tell you which features have been looked at before or do a great job telling you which have human enterable caves. After years of drooling over lidar imagery planning targets, a half-year of trying to secure permits, and months of organizing equipment and personnel, the day had come for a cave expedition to the West Coast. This would be in roughly three parts: the high risk (and potentially high reward) helicopter into a minimally explored edge of a wilderness area (this trip), a few days mapping and exploring in and around the Oparara River, and a few days based at Charleston exploring and mapping at the Nile and Tiropahi rivers. Joel was in charge of personnel, which led to a slightly unusual scenario in that I didn't know half the participants beforehand. I was the last to arrive in-country, which meant everyone else did the shopping and on the ground gear collecting largely before I arrived. This resulted in some annoying shenanigans like buying way too much food, but I was appreciative that I didn't have to be responsible for it. We had a pretty straightforward drive over to the West Coast and booked ourselves into the Last Resort in Karamea, which sadly had gone downhill since the last time I stayed there. Lots of frantic packing and repacking ensued.
We awoke to a nice crisp morning in Karamea, rallied to pack, drove to the aerodrome to meet our pilot Glen, then drove to a paddock at the end of the road on the south side of the Karamea River. We readied our gear in the cargo net and InReached that we were ready to go. Within minutes we heard the helicopter and then had the blast of the propellers temporarily pushing the pesky sandflies away. I sat in the front in the first load, making sure that we had the best landing and campsite before loads two and three arrived. It was a quick flight over a very low flowing Karamea River, then up Cuckoo Creek and past the dramatic sandstone cliffs of Pyramid. Though I had seen them dozens of times in aerial imagery and lidar, the joint-controlled karst fissures and pits on the tussock plateau were still impressive to see in person, a vast area to carefully watch your step. After one loop around, we identified a nice spot to land at the far northeast corner of the Euphrates karst plateau and efficiently emptied the chopper.
Within minutes the chopper was gone. From my past experiences it is not uncommon to feel the abrupt isolation and insignificance of being tiny specks in a vast, seemingly vertically exaggerated landscape, but this wasn't Fiordland and the sunny day and cheerful Dr Suess-esque dracophyllum trees instead presented a friendlier atmosphere. Almost immediately we noticed the gaping dark void of the main entrance of Euphrates Cave at the base of the arcuate bluffs- too bad we weren't the first to find that I thought. My first order of business was to find some water that we could rely on for the next several days. I found a nice following stream a stone's throw away at the base of Garibaldi Ridge: check. The next task was to find a campsite for 10 tents and a kitchen area; nearly all the ground was unsuitably sloping and/or soggy so this proved the more difficult task. After weighing our options, the best was a sloping partially sheltered hollow requiring us to carry all our gear about 300ft from the landing site.
Once the others arrived we shuttled gear and got to setting up camp. Almost immediately curious and troublesome wekas descended on us, looking for any opening to peck or cart away loose items. With others I worked to setup the main kitchen tent with a tarp annex, carving a very comfortable spot out with some effort. Carl masterminded an incredible latrine near the edge of the limestone cliffs, complete with flawless mountain vistas and a view of the Euphrates Cave entrance as a reminder of why we were here. With all the group organizing I was the last to select a tent site and figured it would be slim pickings, but I actually managed to find a nice lump of sphagnum moss on a slight ridge that was better draining than most areas. I struggled to sleep and stay positioned the first night but after that I figured to place gear underneath one side of my sleeping pad to make a more effective platform, and then I was set.
Half of us were content to sit out the rest of the day in camp, while five of us were interested in checking out the steep route at the edge of the scree slope up to the saddle on Garibaldi Ridge- for my prospecting targets to be viable we ended this to be a reliable route both up and down. The saddle was only 300m away from camp but 150m vertically. The route was reminiscent of a half-pipe if it were coated in sharp piercing plants for handholds and mud for feet; the route lured you in with each step being subtly steeper than the last until before you knew it you were clinging to a near-vertical cliff off of small (but apparently well rooted) shrubs and tussocks. I was the first to summit and breathe a sigh of relief until I realized I would have to go back down it later!
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| Our daily plant-clinging commute up the half-pipe of doom |
Once up Brit and I hiked east along the ridgeline following a narrow goat trail centimeters from the abrupt cliff edge. The lidar proved very reliable and we soon got into the swing of marking off choked sinkholes and checking out a few more prominent pits, some requiring rope that we had left back at camp. For a quick scouting mission we managed to tick off about 25 features and worked our way down into the bush. Overall everything we saw in this area was poor quality sandy limestone, but the karst features proved there was subterranean drainage if we could find a way inside. In the bush we were greeted by the usual curious ensemble of robins, tomtits, fantails, and wekas; the whole trip I enjoyed the Americans reactions to these overly curious birds. Nearly out of daylight we returned back to the saddle, this time descending via the ridge immediately to the east; it was great but we got better at the routes over the days. This ended up being the standard commute; up the west spur that was more exposed with smaller plants as handholds, and down the east spur with thicker vegetation that allowed gravity-fed crashing down the steep slope. We enjoyed the first of many excellent sunsets, the foreign Southern Hemisphere mat of stars, and most miraculously, a campfire.
Sunrises were also spectacular, often with low valley-filling clouds creating islands out of the distant ranges. We set into a typical daily pattern. Slow starts, sorting into three groups by motivation/interests, then eventually heading out from camp around 11am. Each day I led a group north down the central valley into the middle of the unexplored karst area. The stream here distinctly lost most of its flow at a prominent joint but unfortunately no human-enterable ways were found. Each day we progressed a little further and spread out to find new features. We found several features with good drafts that were either too tight or needed further digging. Several 5-15m deep pits were descended with handlines or ropes, only to prove blind or too tight in each instance. Further down the valley near the main sink area there was better limestone and some promising features but we continued to be thwarted. Some way, somewhere there was a way in, we just were not lucky enough to find it. The other groups had similarly frustrating results. The most extensive cave I found had about 50 m of passage past a nasty squeeze but no draft or indication of more passage. I searched over a hundred different karst features. It was a lot of planning and effort for not much to show but at least the weather was stellar with only one drizzly day, the views expansive, and the bush very pleasant.
Several deep pits were found in the northwest area, a few requiring ropes to enter. One of the most promising seemed to be revisiting Yesterday's Hole, a 50m deep pit found on the first Garibaldi expedition; a descent to the bottom found it less promising than the description and too tight to continue. On the last day Carl and I traveled the furthest, making it to the edge of the bluffs to the northeast, but still no caves to show.
So after our fly-in day and three solid days of prospecting, we arranged for a helicopter pickup on the fifth day. We left plenty more ground to cover and karst features to check in the future, but it was clear we were not going to find the system I know is hidden within this northern karst plateau that should be larger than Euphrates Cave. Overall the limestone quality was poor and discouraging but someday someone will return and find the elusive cave system. So it was with my personal disappointment and embarrassment of leading 9 other people (8 from all the way around the world) into the middle of nowhere with not promises but strong suggestions of finding caves that we had nearly nothing to show for it. We had one more nice dinner at the Karamea Hotel together as a group before some had to part from us. I huge thanks to Mark who graciously footed the helicopter bill, which took considerable sting out of the disappointment but not embarrassment.
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