Firefighters are expected to continue battling a massive blaze on Glendhu Hill, near Wanaka, this morning.
A Fire and Emergency New Zealand spokeswoman said fire crews were alerted to the fire just off Wanaka Mt Aspiring Rd about 1.30pm yesterday.
Fenz incident controller Jason Sarich last night said the fire was burning in an estimated 180ha-200ha of regenerating bush and was not yet contained.
Wanaka Mt Aspiring Rd at Glendhu Bay was closed and power lines were reportedly on fire as the flames continued to spread.
At 8.30pm 10 fire appliances and eight helicopters were fighting the fire, and another aircraft was co-ordinating the air attack.
The aircraft were expected to stand down from about 9.30pm but some of the ground crews were staying at the scene during the night to monitor the fire.
A wind shift was forecast overnight, which had the potential to move the fire closer to a small number of properties at Emerald Bluffs, Sarich said.
Fire personnel had been in touch with those residents to alert them to the situation. Fenz was also liaising with police and Emergency Management Otago in case precautionary evacuations were required
About 30 cars had been stuck on either side of the fire, but they were given access to pass through just before 6pm. The road remained closed to other traffic.
It was unclear how the fire started, and a fire investigator was expected at the scene today.
Glendhu Station owner John McRae owns the land neighbouring the fire, including popular mountain biking park Bike Glendhu.
McRae said he believed the fire started at the Glendhu Bluffs above Emerald Bay. He estimated 50ha to 100ha of land had been affected.
After emergency services and helicopters were contacted, he made the call to evacuate the park as a precaution.
Part of the fire area was formerly owned by Glendhu Station and had been retired for native bush regeneration, McRae said.
His family had owned the station since 1969 and he had never seen a fire like it there.
"This land in here is actually DoC estate and it's all beautiful native bush, so all sorts of different varieties of plant — very hard to replace.
"In Glendhu Station's history that bush has never been cleared, so it's been there my whole life.
"I'm 46, Dad has been here a bit longer than that ... and today for some reason it decided to burn.
"It's just one of those sad days — but it's not people's lives, it's not livestock, it's not houses and it's not other things," he said.
"[The bush] will grow back."
A Department of Conservation spokesman said about 6pm the fire had also spread to DoC land.
He confirmed DoC would be sending in DoC firefighters to help quell the blaze this morning.
Matukituki Valley farmer Kate Stewart and her family were returning home when they found themselves caught out by the road closure.
Stewart entertained her children Rosie (11 months) and Isla (3) with a picnic in a paddock to pass the time.
"There's quite a few of us caught by it," she said.
"Our shepherds are coming home from Cromwell — we've told them the road's closed."
The nearest house was about 5km-6km away from the fire, so she was not concerned about her house, she said.
"It's such a beautiful place, so for something like this to happen ..."