"The first young fellow had run all the way [to State Highway 6]. It was a great effort. It was a long way off the road . . . It was a tragedy to lose one. But when you see the scene, it was a miracle we didn't lose more."
It is reported that Clausen, his partner and their children have lived in the tiny Makarora community, about 63km northwest of Wanaka, for many years.
Senior Sergeant Allan Grindell of Wanaka told Fairfax the family were "grieving pretty bad".
"It was a pretty brave and determined effort by those two young boys, considering they would have been knocked around. I concur with their [firefighters'] praise," he said.
Police are still investigating and hope to release more information in the next few days.
The group of four were on a four wheel drive trip in the Boundary Creek area of Hawea Conservation Park. Their vehicle left a narrow track and plunged about 50m down a steep bank.
The track is known to be difficult, with areas where it is impossible to turn around.
There was no cellphone or radio reception at the accident site, which was about 810m above sea level and more than 6km from Boundary Rd camp beside Lake Wanaka.
Lake Hawea deputy fire chief Kevin Cappell told Fairfax the area was "very remote".
"The drive up the front face is all right but it is quite steep, quite gorgy, not very good. I was in there a few years ago, opened it up with an excavator. But the whole area is unstable. It is not a good track at all."
