The woman and her husband, both from Germany, were on a toboggan run from the Maria Waldrast pilgrimage site down to the village of Matrei am Brenner.
After the woman collided with the fence, she told her husband she was fine, and they both continued their run.
However, a short time later the man saw his wife had become unconscious, and immediately called emergency services.
Despite first aid from the German man and other toboganners, the woman died before an ambulance could take her to hospital.
The Maria Waldrast toboggan run is one of the most popular runs in Tyrol.
A judicial autopsy has been ordered to determine the cause of death.