Rock Burn – Lake Unknown

19 – 24 March 2021

Three left Christchurch at 7am to pick up Helen at Ashburton and with only short breaks along the way the foursome was able to set off from the Routeburn Shelter at 4.15pm for Sugarloaf Pass. We carried on to the Rock Burn, pitching the tents by the river, in the dark, having walked 8.2km in just under 4.5 hr.

This was a good starting point for the climb up from Theatre Flat. The day dawned murky with low cloud so we were a little concerned about traveling across the tops. We made good time to Theatre Flat, where we followed the route in Moir’s Guide, North and “bush bashed” our way up the true right of a small stream, finally clearing the bush. The cloud suddenly lifted as we reached a set of bluffs at the head of the stream. Picking our way up the steep rock slabs to the saddle between Minos Peak and point 1760, we were rewarded with panoramic views of the surrounding peaks and Lake Unknown. From the saddle, we descended tussock slopes to camp by a small lake below Minos Peak, having travelled 10.3km over difficult terrain in 8 hours.

Day 3 dawned chilly but calm and clear. We sidled under the bluffs of Minos Peak, across a large rock-fall and then climbed up a steep tussock and scree slope to the rock slabs and scree fields below Mt Chaos. At this time of year, the snow had receded enough that our crampons and ice axes were not required on the steep sections –better to have and not need, than not have and need! Dropping into a beautiful hidden valley with pristine stream, between Amphion Peak and Minos Peaks, we stopped for lunch and to dry our tents on the shingle flats. We crossed a saddle and then traversed rock slabs and benches between 1500 -1600m on the southern side of Amphion Peak to cross over the outlet of Park Pass Glacier. This area was truly awe-inspiring and the cameras were busy recording the amazing scenery. From our vantage point, we could see a large group camped on Park Pass, and wisps of mist and cloud beginning to wrap themselves around the peaks. Dropping down to Park Pass was straightforward, having travelled almost 11km over testing terrain in 9 hours. We arrived just in time to set up camp by an unoccupied tarn before the mist came rolling in.

Day 4 dawned very cold and windy with thick mist, so forgoing a morning brew up, we descended to Theatre Flat for a mid-morning brew and late lunch by the river. The weather cleared late morning to a warm sunny day and we had an enjoyable wander down the river, across the flats and through stands of beech forest. The last punch up to Sugarloaf Pass was draining but camping on the pass rewarded us with great views of Mt Earnslaw and the surrounding peaks. The extra effort would give us more time for next day’s long drive back to Christchurch. This section was 15.3km over 8.5hrs.

Day 5 dawned fine and we enjoyed the beautiful bush and cries of kea and kaka. We were sad to be leaving, having forgotten the hard terrain, we basked in memories of a fantastic trip.

Thanks to Raymond for his superb leadership and navigation skills, ensuring that we all felt confident to enjoy a very special, seldom-visited area.

We were: Raymond Ford, Peter Umbers, Merv Meredith and Helen Binnie (HB).


Climbing to the saddle below Pt1760. Nereus Peak in the distance. Photo by Raymond Ford

Lake outlet, Park Pass Glacier, looking up to Poseidon Peak. Photo by Raymond Ford

Lake Unknown and Mt Nox. Photo by Raymond Ford