Search and Rescue (SAR) co-ordinator Senior Constable Julian Cahill, of Queenstown, said people usually died from such falls.
"He fell on rocks but we think he may have landed on his pack. He is incredibly lucky to be alive," Snr Const Cahill said.
Kladno Holuska (29), understood to be from a village near Prague in the Czech Republic, had been on a Buckler Burn track near Judah Rd with a male companion, also from the Czech Republic, about 1pm on Saturday.
The pair were heading for the McIntosh Hut when Mr Holuska "somehow got off the track and went into a 30m freefall off the cliff on to the riverbed of the Buckler Burn," Snr Const Cahill said.
His companion could not climb down the cliff but could see Mr Holuska was still moving and ran 4km to Wyuna Station to raise the alarm.
Wyuna Station farm manager Alistair Wallace then called Glenorchy first-response paramedic Callan Grimmer, who activated the Glacier Southern Lakes helicopter, which was the on-call SAR unit.
"In the meantime, Callan and Alistair and three advanced paramedics who happened to be off-duty in Glenorchy drove up Judah Rd to a point above the victim. Callan then, in his words, shimmied down.
"I must say, having observed the terrain from the air, I admire his efforts in getting down there - there is some very difficult and steep terrain and heavy vegetation," Snr Const Cahill said.
"I just shimmied down the bluff," Mr Grimmer said.
"It was a wee bit hairy - just another day at the office."
When he reached Mr Holuska, who was still conscious and had been alone for about 90 minutes, "he had a lot of blood loss, he was pretty banged up, in a lot of pain and in shock," he said.
"It's a hell of a big drop. If you get off the track, it's very easy to come unstuck. He's lucky to be alive. If he'd been off to the side, he would have landed on bigger rocks," Mr Grimmer, an experienced tramper and operations manager of Dart River Jet, said.
After first aid was administered, Mr Holuska was put on a stretcher and lifted by helicopter from a nearby bank.
He was then flown to Southland Hospital, accompanied by St John Wakatipu paramedic Keith Raymond.
Mr Holuska broke his left thigh and wrist in the fall, and suffered moderate bleeding and bruising to the head and face and double compound fractures in his lower right leg.
"The bones were poking through the skin," Snr Const Cahill said.
Snr Const Cahill praised the actions of all involved in the rescue, which was undertaken in unforgiving terrain with limited communications.
"They were outstanding - I think he would have died if he'd been alone and we hadn't found him - so there's a little lesson here for people going into the hills."
A Southland Hospital spokesman said yesterday afternoon Mr Holuska was in a stable condition after surgery yesterday morning.
