By making a successful ascent of the west face of Tutoko, Guy McKinnon has completed what had been described as one of the greatest remaining mountaineering challenges in New Zealand.
Tutoko, at 2,746m, is the highest point of the Darran mountains, a range in the southwest corner of South Island that is noted for extreme rainfall and distance from any population base.
In 2010 the New Zealand Alpine Club's magazine The Climber published an article entitled The Great Unclimbed, which profiled the six major unclimbed mountaineering routes in the country.
The west face of Tutoko featured highly, as with a vertical gain of 1,900m it was the biggest unclimbed face in New Zealand.
This steep alpine wall had only been attempted once: in the summer of 1974 Dave Bouchier, Butch Hill and Pete Moore reached the headwall before turning back.
Difficult access, the perceived length of time required for the climb, and a reputation for poor rock, meant the face received little subsequent interest.
However, an ascent in early winter, ie July, after heavy June snowfalls and the right weather patterns might allow ice runnels to form in the lower section, seemed logical.
But even reaching the base presents its own problems. On one recent attempt a competent party was psyched out by the colossal avalanche debris adorning the head of the cirque from which the face rises.
The article in The Climber suggested that three days would probably be needed for the ascent (with a long day before to reach the foot via the Tutoko Valley), after which a descent of the 'standard' route - the northwest ridge - would be very long and not easy.
All of which makes McKinnon's solo ascent of the face in just eight and a half hours more remarkable.
Starting from a bivouac at the base, McKinnon climbed the central weakness on this wall, which is bigger than the Eiger north face, finding superb conditions and reporting nothing overly hard, just "lots of it".
He graded the route VI, 4+. This is a Darrans ice grade, which is not exactly comparable with the French or Canadian system. However, as with French grades, VI does represent the overall commitment level: McKinnon noted that if the Darrans system was open ended, the face would probably be VII.
McKinnon reached the summit and descended to a bivouac on the crest of the northwest ridge.
Next day he tried to continue down this ridge, but was unable to get out the bottom. He was forced to re-ascend, then descend the north face to the high glacial basin of Ngapunatoru Plateau, and eventually down to the Tutoko Valley, from where he reached the roadhead after a continuous 21 hours of travel.
Tutoko was first climbed in 1924 (via the northwest ridge) by a British resident Samuel Turner and the legendary New Zealand guide Peter Graham. It was Turner's fourth attempt on the peak, beginning in 1919, his third ending only 200m below the summit.
For 37 years old McKinnon, this was his third attempt on the line. In 2011 it appeared a little too hard and frightening, and in 2012 he was thwarted by poor weather.
In 2010 he became the first person to make solo ascents of all 34 New Zealand peaks above 3,000m.
And the other five great problems? These are considered to be the east face of Pope's Nose Direct in winter, South face direct of Mt La Perouse, Southwest face of Mt Percy Smith in winter, North face of Mt Sefton, and the Cyclops in the Darrans.
Pope's Nose Direct with its difficult access, and Percy Smith (although 800m and therefore relatively small), are thought to be hard technical propositions.
Thanks to Damien Gildea for help with this report