Four people were taken to hospital after the incident on a slip-ridden rural road near Leigh.
Emergency services rushed to the scene, on Ashton Rd in Whangateau, around 8.50am.
An Ashton Rd resident told The New Zealand Herald she could see a helicopter, three ambulances, at least two police cars, and three to four fire trucks at the sight of the crash.
The top part of the street had been blocked off because of the slips so the neighbours had been using quad bikes to go up and down the road while repair work was being carried out, she said.
She said she was not sure what had happened today but someone was definitely hurt and “there were access problems to get to the person injured”.
“It is a bit of a worry.”
The Auckland Westpac Rescue Helicopter was tasked to the remote to assist a female patient in her 40s and two children suffering “a fall of 50 metres on a quad bike down a muddy bank”.
“The woman needed to be extracted by winch from a height of around 200ft,” a spokesperson said.
“She was flown to Auckland City Hospital in a serious condition.
“The children were in moderate and minor conditions.”
