Senior Station Officer Ross Beddows said two fire crews were the first emergency services on the scene, after a nurse travelling to Kaitaia found the crash. She clambered down the hill to assist, and was able to brief the fire crews on the injuries to the two survivors.
"We are very grateful for her efforts and the assistance she provided," he said.
It appeared that at least two of the occupants had been thrown from the utility shortly before it stopped rolling, he added.
Both survivors were stabilised by St John ambulance officers from Kaitaia and Doubtless Bay before they were carried back up to the road by firefighters and police.
Firefighters had initially dropped a line down the bank to reach the scene, but later found a farm track that gave them easier access.
The Police Serious Crash Unit is investigating the crash, which took Northland's road toll for the year to 20, one more than in 2014.
Meanwhile an elderly woman emerged unharmed after she lost control of the car she was driving on SH10 just west of Branko's Hill on Saturday afternoon.
The car, which was travelling west, crossed the centre line, crashing through a fence, travelling more than 100m through a large vegetable garden, cutting a swathe through rows of corn, cabbages and radishes, through another fence and into the backyard of a house on Tahanga Road, finally crashing into a sleepout.
Police believe the woman, who was the sole occupant, had lost consciousness after taking medication. She was assisted from the vehicle by St John ambulance officers, and taken to Kaitaia Hospital as a precaution.
Mr Beddows said all the car's airbags had deployed upon impact with the shed, no doubt saving the woman from injury.
"It seems the accelerator remained down all the while the vehicle was traversing the garden, a trail of uprooted veges indicating the path it had taken."
