Tarawera Ultramarathon organisers have announced a new Tarawera 100 Mile Endurance Run.
The race will be part of the Tarawera Ultramarathon race week that culminates on February 10 next year. It is expected to attract 800 runners in its inaugural year, of which more than two-thirds will be international.
''We expect it will become one of the largest two or three 100 mile trail ultra events in its first year,'' said organiser Paul Charteris.
The winners will be expected to cover 161km in around 15 hours while the final finishers may be closer to 38 hours on the trails.
With runners and their supporters staying an average of four nights in Rotorua, the potential economic impact for Rotorua will be in the millions.
Charteris said the ''100 miler'' was the gold standard of trail ultramarathon distance running worldwide.
''While there are more than 400 races around the world, there are very few events to choose from in either New Zealand or Australia.
''We expect large numbers of runners to come from Australia and the United States and should continue to see growth in Asian markets, which have been doubling, in number of runners each year for the past three years.
''Perversely, for many fans of the sports, the 102km Tarawera Ultramarathon distance is not considered a long enough run to justify an overseas trip to New Zealand.''
Putting on the 100 mile event had been a decade long dream, said Charteris.
''The reason we have waited so long to put on this event is because it has taken several years to put together the dream team who can safely manage and deliver an event of this magnitude. Issues with remote communication, safety and medical and become of paramount importance in an event of this scale.
''With runners doing battle through the day, night and into the next day, there is plenty of scope for things to go haywire - so we have to be extra vigilant and have many teams capable of looking after runners and their supporters over a two day continuous event.''
The organisers plan to announce further details in July or August as the course is finalised. Entries for the 2018 Tarawera Ultra open on June 1 and earlybird entrants will have the option of upgrading their entry to the 100 mile distance.
Now in its tenth year, the Tarawera Ultramarathon has become a bucket list run for athletes across the world, with more than 50 per cent of the field from overseas, representing 45 countries.
The event is also part of the Ultra-Trail World Tour, a series of the most prestigious ultra-running races in the world.