"Remarkably, she had no apparent injuries other than a bit of hypothermia.
"It seems pretty lucky to me. The car was 30 or 40 metres down the hill, she was 50 or 60 metres from the car, so to have no injuries is remarkable."
Mr Greenberg said the woman had got out of the car, was confused, and had made her way down the hill.
Featherston fire chief Colin McKenna said his crew were called to the scene around 10.40pm on Thursday, and arrived to see "a hole in the fence and a car down the bank".
"Two of my guys went down and did a search of the area but it's dense bush up there, really thick."
A specialist high-angle rescue crew from Porirua Fire Station were called in, then a Wairarapa LandSAR team joined the search, and located the woman.
Mr McKenna said he did not think it was a dangerous road.
"You drive to the conditions. It's not really a dangerous road, but it's pretty windy. There didn't appear to be any skid marks, but exactly what happened I don't know."
Masterton police Acting Senior Sergeant Rob Rackliff said a member of the public who had noticed the damaged fence had called police to report the matter.
A Wellington Hospital spokesman said the woman was discharged yesterday morning.