The extended family, who are recent immigrants to New Zealand, had travelled from their home in Lower Hutt and were driving up the Turoa Skifield road when the accident happened on Sunday afternoon.
The minivan rolled twice on a corner before plunging off the road and down the bank.
Ambulance, Fire Service and two rescue helicopters rushed to the scene, about 9km up the mountain from Ohakune.
Ohakune chief fire officer Ben Goddard described the scene as like a sea of injured people lying on the bottom of a ravine. Three adults and five primary-school-age children were in the vehicle when it crashed about 4.30pm.
Several had to be cut free from the wreckage.
Each was then individually winched up the steep bank.
The Taupo-based Lion Rescue helicopter took the driver - a 36-year-old man with multiple injuries - and an 8-year-old girl with head injuries to Wanganui Hospital.
The other adult and four children were taken to the hospital by ambulance.
The hospital spokeswoman said four of the group had to be admitted with moderate injuries.
The others were treated for minor injuries.
A translator had been brought in as the family spoke very little English.
They were all staying on site until the mother was well enough to go home, the spokeswoman said.
Square Trust pilot Dave Fielding said the family were fortunate to have escaped more serious injury.
"When you saw the scene you realised the whole family were very, very lucky."
Mr Goddard said the road was completely closed at first, then was down to one lane for more than an hour, causing some traffic headaches for holidaymakers.
