Olivine Ice Plateau
7-15 February 2023
On the 2012 PTC trip to the Olivine Ice Plateau the area was enveloped in cloud so Gary suggested a repeat trip to see the views. Geoff was not keen on repeating standard routes that he had done many times before but there was, however, another possibility. Years ago, Geoff had bashed his way down the Barrier Stream gorge to the Pyke River, but he had never been up Diorite Stream to the Barrier via Beresford Pass, so that became the trip plan. The only trouble would be the notorious Olivine weather. After much deliberation and a three-day delay to get a fine period, we headed for the area. We needed an early start from Christchurch to reach Glenorchy and place a car at Chinamans Bluff before flying finished for the day. A helicopter was the only practical way to get to the Olivine Hut at the junction of the Olivine and Pyke rivers, and it was an exhilarating ride along the Five Pass route of the Rockburn, Hidden Falls and Olivine Rivers.
Day 1 of tramping started with an exciting cable-way ride across the still-swollen Olivine River, then a bush lawyer and cutty-grass traverse to the base of the Olivine Falls. They were just as impressive in the relentless rain as the fine-weather view from the helicopter the day before. We swamp-bashed up the Pyke towards the start of the Diorite to commence the 800m climb to the upper basin—hard going with heavy packs. The rain made everything slippery, small cliff-lines barred the way and supplejack caught on every projection. We finally started to find deer trails but, every time they seemed to level off towards the flats, they would take an abrupt turn straight up the hill. We finally reached the magic 800m contour and traversed to the large, impressive flats, just as the sun came out. We hurriedly pitched tents in an open gravel area before rain come up the valley again.
Day 2 dawned misty as we headed for Beresford Pass into Barrier Stream, with only a 600m climb ahead but a 700m descent. Tough alpine scrub and long tussock slopes led to upper scree where an inquisitive chamois peered over the pass. The view into and across the Barrier River was welcome and impressive with bare, red ultramafic rock around Stag Pass. Navigation down was difficult. Faint deer trails petered out amidst large moss-covered boulders. It wasn’t easy keeping close to the stream, heading to the crossing point at 840m but finally we crossed to find old cairns and a well-defined deer trail down the prominent spur. Luxury! The flats provided somewhat swampy travel, while the forest sections were covered in gaiter-deep moss but were a relief after the day’s ascent and descent. A delightful campsite at the Barrier Forks had to be cleared of deer before we pitched camp in heavy showers. We glanced uneasily at the high, discoloured South Barrier River that we would have to cross in the morning.
Day 3 delivered fine weather and crossing the South Barrier proved easy, some distance above the forks. The vista from the head of the Barrier Flats was inspiring. Darkness Peak was prominent and we could see the full extent of our route underneath Ark, providing access to the Plateau. The bush-line on the ridge that we had to climb didn’t look too far, only 400m but it was a steep 400m and the alpine scrub proved as resistant to pushing as the supplejack climb up the Diorite. Gaining the bush-line was a relief, and gave views of the Furies and Darkness Peak. Traversing and climbing brought us to a campsite above the large tarn at 1400m with impressive views down the Barrier and across to Intervention Saddle and the promise of fine weather for the climb to the Plateau.
Day 4 started with thick cloud on the Plateau that would make navigation difficult and ensured a slow start while we debated the options. It finally started to clear and up we climbed, first along a tussock ridge, then a rocky terrace below bluffs, ending in a dramatic break in the ridge with no obvious way down. The ridge was our only route, so we backtracked, down tussock ledges to finally gain the gully, then up again to slabs on the ridge. The snow route that we could see from the Barrier flats was reached, then it was up into the thickening cloud for the traverse under Ark. Mist had turned to drizzle as we reached the ridge, directly under Ark, too high to descend directly to the Plateau. Threading our way past spires dimly seen in the mist, we reached Pic d’Argent Col, the door to the Plateau. Unfortunately, it was impassable as the snow had retreated, leaving a 20m cliff separated from a 10m wall of snow. Geoff went prospecting left amongst the rock spires, but returned without success. He then joined Raymond, who had found a rock bench higher up the ridge towards Ark. It was steep but provided a route down the cliff face, with some pack-passing and bum-sliding and led to the inside of the snow wall. Step cutting and belaying up the steep face finally gave us access to the Plateau.
Navigation was then an issue through the maze of crevasses in fading light and thick cloud, with GPS, compass and dead reckoning finally leading to rock ledges and camping possibilities. Multiple camp possibilities were viewed and discarded before pitching tents near a small tarn, then enjoying Peter’s dinner, well past our normal bed-time.