More than 350cu m of rock and debris blocked road access to the Matukituki Valley and the main Wanaka road through to Mount Aspiring National Park, yesterday morning.
The fall was discovered by a staff member of Treble Cone skifield about 5.30am, when the groomer operator travelled in to begin work, a council contractor said.
An earthmoving digger and loader were called in to clear the road of debris, after the bluff rock face had been surveyed by contractors.
A helicopter and monsoon bucket were also employed to drop water on to overhanging slabs of rock at the site, which contractors initially believed might have been unstable.
"[The rock fall] could have potentially been caused by the Christchurch earthquake, but we are also talking about a fragile geotechnical area at those bluffs," he said.
Treble Cone skifield could not open yesterday morning because the blocked road cut access for staff and visitors, operations manager Rosco Davies said in a recorded phone message on the skifield's snow report.
Strong, gusty wind and rain showers from a northwest frontal system swept across the Upper Clutha yesterday morning.
The weather and gale-force wind also shut down the skifields of Cardrona Alpine Resort and Snow Park NZ. Pisa Range nordic skiing facility Snow Farm opened, despite 40kmh winds.
