"I'm a positive guy and I'm not thinking about dying there."
The young German - on a weekend off from his Matamata dairy-farm job - lost his phone in the fall, so screamed to attract attention. He said the pain was very intense - "10 out of 10".
"But after about 20 minutes or so I decided there wasn't any help for me and I was alone ... I took the bands [laces] from my shoes and fixed my broken leg together with my right leg. I lay there for another 20 minutes or so and thought about my situation and what is the next step for me."
Mr Drees had lost his footing on a path in the Te Heuheu Valley on the northwestern side of Ruapehu on Sunday morning and slipped 50 metres down a slope before his left leg crashed into a boulder, smashing it and causing an open fracture.
He then slid a further 50m before stopping himself on another rock with his right leg. "No, it was not so cool," said Mr Drees, who was walking alone after doing the Tongariro Crossing solo on Saturday and mountainbiking in Taupo the day before that.
With his legs tied together and a shirt stemming the bleeding, Mr Drees saw a lift station about 300 metres downhill and made his slow and painful descent, using his elbows to control his speed.
He spotted a man in his 50s and his daughter near the Knoll Ridge cafe and screamed for assistance.
They wrapped him in a jacket and gave him water and a muesli bar before calling for help.
Members of the Ruapehu Alpine Rescue Organisation turned out, and the Taupo-based Greenlea Rescue Helicopter flew him to Rotorua Hospital.
"I want to really, really thank them in some way for helping me," Mr Drees said.
"I was very, very lucky. It could have been a lot different. I could have gone on a bit longer, but I don't know how much longer."
Mr Drees said he had been enjoying his weekend off from his farm job and "had nothing to do on Sunday" when he decided to hike up Te Heuheu Valley.
He said he would never go up a mountain alone again. He was an experienced mountain climber and fit, but said the only person who knew what he was doing was someone he had met at an information centre in National Park.
Leonce Jones of the Mountain Safety Council said people saw Ruapehu as a nice one-day tramp, but conditions could change dramatically.
"It's not stable ground. There is always a chance you will slip and fall, as was the case here."
Mr Drees was extremely fortunate that he had kept his head and it was warm.
Mr Jones said the rules for heading into the mountains were simple: go prepared, let someone know where you are, take plenty of food, water and warm clothing and a means of communicating.
A police spokesman said while Mr Drees did exceptionally well to drag himself so far, he was ill equipped for alpine conditions and wearing only street shoes.
Mr Drees said he would likely be off work for at least three months and was unsure how this would affect his plans to stay in New Zealand until early next year.
