"The deceased has slipped on the edge of the track and lost her balance falling down the bank," he said.
"Unfortunately the slope was steep enough that she could not arrest her fall and she slid backwards approximately 40m before dropping over a 3m bluff onto a rocky creek bed below.
"There were two doctors in the tramping party that did as much as they could for her but the injuries sustained in the fall were significant and unfortunately she died at the scene."
The woman was among a group of 22 in native bush when she slipped and fell about noon.
Police were notified at 12.09pm and a helicopter carrying two Wanaka search and rescue personnel and a paramedic left Wanaka about 1pm.
They returned a short time later to unload equipment, including an empty stretcher, before returning to the track.
The woman's body was then brought to Wanaka by helicopter.
The death would be referred to the coroner, Mr Grindell said.
The walkers group regularly undertakes trips in the Wanaka area on Mondays.
According to its blog site, the group yesterday planned to climb through the beech forest to the bush line for lunch.
Some of the group had intended continuing on to the Fern Burn Hut.
Walking group member Rod Macleod, of Albert Town, described the accident as a tragedy.
Mr Macleod said the track was built by the Department of Consveraction (DoC) six or seven years ago.
He declined to describe the area of track where the woman fell.
In 2005, when DoC was securing access to the area for the public, then Otago conservator Jeff Connell described a short section of the proposed Fern Burn track as "incredibly difficult".
Negotiations over public access stemmed from the purchase of Motatapu Station by Canadian singer Shania Twain and then husband Robert Lange.
The Otago Daily Times reported in February 2005 Twain's preference was for the track to follow the Fern Burn, which was on Alpha Burn station land, rather than an alternative route nearer their proposed house.
Twain's neighbours, the McRae family, did not want the track to go up the Fern Burn because it would pass their deer paddocks and would affect their farming operations.
They also believed the route would be treacherous, the ODT reported.
It was unclear last night whether the accident occurred on this section of track.
A DoC spokeswoman said it was likely the department would produce a report for the coroner.
