He immediately set off an emergency locator beacon.
A rescue helicopter was unable to land in the high country and by the time a second helicopter from Greymouth was called in, the father had died at the bottom of the ravine.
The son was winched to safety about 7pm yesterday.
Greymouth police Senior Sergeant Brent Cook said the man died in an area near where Swedish tourist Hans Christian Tornmarck died last month.
"It's roughly in that area, not exactly there. It's pretty rough country through there."
Cook said he was currently liaising with the family of those involved.
He said it appeared the son did everything he could to help his father.
A formal identification will take place later and until it had been completed, police were not in a position to release his name.