A Wanaka woman was airlifted from Aoraki-Mt Cook National Park on Friday morning after her foot was crushed by a boulder.
She was among a party of four people who were descending towards Caroline Hut after tramping the Ball Pass route on Thursday.
Police say a rock moved from underneath her and caused a boulder to land on top of her foot. The incident happened at about 8.30pm and police were alerted an hour later.
However, a helicopter from Christchurch was forced to turn back because of bad weather.
Senior Constable Brent Swanson says she was reached just before 7am and taken to Timaru Hospital for further treatment.
Mr Swanson says it was fortunate that the group was well-prepared.