The injured family - a man, a woman and two small children - were treated at the scene by St John before being transported to the Wanaka Medical centre for further assessment.
Senior Sergeant Allan Grindell believed the driver, a man, had injured ribs.
The Prado Landcruiser was travelling towards Wanaka from Cardrona and failed to negotiate a bend on a slight hill, about 2km south of Spotts Creek.
Constable Mike Johnston said the vehicle narrowly missed a power pole twice - going up the bank and coming back down.
• Two motorists escaped injury when the cars they were driving collided at the crash-prone intersection between Frankton-Ladies Mile Highway and Glenda Dr, near Queenstown, yesterday.
A middle-aged man from Manapouri was sitting stationary in a Toyota Landcruiser at the stop sign on Glenda Dr about 11.20am.
A woman aged in her late 20s was driving a Holden Commodore car west along the highway towards Queenstown when the man pulled out and the vehicles collided, Constable Richard Clarke, of Queenstown, said.
Both drivers were the sole occupants of their vehicles. The woman was assessed for injury by St John Queenstown and released at the scene.
Frankton and Queenstown firefighters attended.
