Poor decision-making contributed to the deaths of two teenage women in an off-road crash near Nelson last year, a coroner says.
The pair, whose names are suppressed, were returning from a hut in Mt Richmond Forest Park late on 8 April when their ute rolled 98 metres down a steep bank.
The 18-year-old women had intended to stay at Beebys Hut but told a friend in a video call they were cold and were driving back down the mountain.
Police were notified of the crash at 11.01pm by an automated emergency alert from one of the women's phones.
Coroner Peter Ryan said the women were found dead at the scene and both had been ejected from the ute as it rolled.
Neither had been wearing seatbelts, he said.
"Although there is no evidence to indicate whether either or both of the women would have survived the vehicle rolling down the steep hill had they been wearing seatbelts, common sense dictates that wearing seatbelts would have prevented the two young women from being ejected from the vehicle as it was rolling down the hill," he said.
Toxicology reports and videos the women recorded earlier in the evening showed the pair had been drinking.
Coroner Ryan said the woman who was believed to be driving at the time of the crash - as stated by the friend they video-called earlier in the evening - was nearly three times over the adult blood-alcohol limit.
But at her age the legal blood-alcohol limit was zero, the coroner said.
There was no evidence suggesting the driver had been using the ute in a reckless or erratic manner, Coroner Ryan said.
But he accepted a conclusion in the Serious Crash Unit report that alcohol impairment was likely to have been a causative factor in the roll-over.
"It is likely that, due to the amount of alcohol she had drunk, [her] judgement and decision-making was impaired, and she misjudged the steepness of the slope and the capability of the vehicle she was driving, and may have over-estimated her own ability to drive over such terrain," he said.
Coroner Ryan found the pair had been driving about 200 metres off the formed track and after dark, in breach of Department of Conservation access rules.
He noted the woman believed to have been in the passenger seat had picked up the key from the DOC office and been given a copy of the conditions of access, raising the possibility the driver was not aware of the rules.
"However, I note that there is signage on the track which notifies all drivers of the requirement to remain on the track," he said.
The ute could not be recovered from the crash site for a mechanical inspection, Coroner Ryan said, but a crash analyst found it unlikely there were any faults that might have contributed to the crash.
The women were described as close friends who loved the outdoors and adventures.
Both died from multiple severe injuries.
