"We hoisted in one of the police guys, he managed to get her out," said rescue chopper pilot Lance Burns.
"I think there was a mother and someone else down the bank where she was. We extracted her, stabilised her with the paramedic."
They were able to hoist the girl out to the chopper.
The teenager suffered numerous injuries to her chest, back and pelvis.
Burns said the quad bike the girl was on had plunged all the way to the bottom of the drop, with the girl herself only falling about halfway, which was still about 30m.
Taihape Fire Brigade senior station officer John Collings said trucks from Taihape, Mangaweka and Whanganui all attended the scene, and the Whanganui rope rescue team came in to help.
The crews gathered on Zohs Rd for the rescue, which took a couple of hours, he said.
Whanganui senior station officer Jemal Weston said the rope rescue team were called in to help the other rescuers back out of the bush.
The girl's mother and another local man were down in the area she had fallen to and needed help getting out of the steep spot once the girl had been winched by the helicopter.
If weather conditions had made it hard for the helicopter to fly, the mission would have been much different, Weston said.
"As it turned out, luck was on her side. She's very, very lucky to be alive."
A St John spokeswoman said the girl was treated at the scene before she was flown to Whanganui Hospital in a serious condition.
This afternoon she was in a serious but stable condition, a hospital spokeswoman said.
