On April 3, it will be four years since cancer took Mr Ulriksen's wife, Bronwyn, and he is marking the anniversary with the epic run.
Chile has another attraction for him; his father came from the South American country.
For two months he plans to run between 50km and 60km a day in all weathers and often mountainous conditions, but he does not think he is a runner at all.
"I don't really consider myself an athlete, it is just determination," he said.
The former Queenstown resident, who is planned to return to the resort after the run, said running had been a way of dealing with the grief of his wife's death and it helped to keep him productive.
"I could sit on the couch. I tried sitting on the couch, but I couldn't. I needed a different kind of high," he said.
Mr Ulriksen said running was a good metaphor for cancer because it took you through the highs and lows, the good and the bad days.
"Unfortunately, there are those who don't get through cancer. But one thing cancer teaches you is: it is not the end result, it is about the journey."
On average he has been running 20km a day to get up to speed since he was forced to have all of December off after developing an injury while in Thailand.
The run will begin at the northern town of Arica and finish down at Puerto Montt, in his quest to raise money for the Chilean Cancer Foundation.
Apart from a small support team, Mr Ulriksen will be running solo.
"I hope to run 25km in the morning, 25km in the afternoon and a shorter run in the evening."
This is not the first time the 40-year-old has taken to the pavement for a cancer charity.
In 2008, he walked 2400km from Adelaide to Brisbane, raising more than $20,000 for the McGrath foundation - a fund set up by former Australian cricket fast bowler Glen McGrath after his wife died of cancer.
"Once you get to five days, the body gets used to the pounding."
The first walk was inspired by both his late wife and his father, who died of lung cancer during Bronwyn's diagnosis period.
"It came from a joke with Dad. He said to me while we were driving from Adelaide to Brisbane, 'When I get better we will walk back'."
Before he began his running mission Mr Ulriksen weighed in at 120kg and now proudly weighs an impressive 40kg less.
"It's good for your health, that's for sure.""I hope it raises awareness, raises hope for others and just lifts spirits of people who are going through what Bronwyn went through."
