A woman has been airlifted to hospital after falling 150 metres down a slope in Mount Cook National Park.

The 48-year old was rescued from the Copland Pass area, where she had fallen down a snow slope and hit rocks at the base. She suffered minor injuries and was flown to Christchurch Hospital just after midday.

Department of Conservation Alpine Rescue Team head David Winterburn says damage to the woman's helmet indicate she may have suffered more serious injuries if she had not been wearing it.