The race is usually held on a steep, high-altitude course at Northburn Station, near Cromwell, in March and station owner Tom Pinckney told the Cromwell Community Board yesterday ''in light of a recent tragic event'' on the station, both the 161km and 100km races would be cancelled for 2015.
He was referring to the death of Peter Grayland (52), of Alexandra. Mr Grayland, who worked on Northburn, died during a burn-off on the station in early September.
His death was referred to the coroner. Mr Pinckney, who is a community board member, told the meeting yesterday it was important when running events which were ''on the edge'' to ''make sure that all our i's are dotted and our t's are crossed''.
After the meeting, Mr Pinckney said the decision was ''not made lightly''.
''The owners and management of the race are very aware of the time, effort and commitment competitors have put into training and general preparation for Northburn in March.
''However, given the recent tragic events on Northburn and the very real danger that they face as ultra-runners [especially at a high altitude event such as Northburn], we feel it is prudent do everything possible to ensure their safety at future events.
''We want to assure everyone that the safety of all people on Northburn is paramount and we want to make sure we have left no stone unturned in that regard for the 2016 event and onwards,'' he said.
The 100 mile (161km) race was first staged in 2011.
The 50km section of the event, the half-marathon and children's events would be staged as usual in March and new safety initiatives would be trialled during the 50km event, Mr Pinckney said.
