Two men have been seriously injured in a head-on crash on State Highway 10.
The crash occurred about 6.40am yesterday near the Whitehills transfer station, about 1km south of the Matauri Bay turnoff.
With no viable detour and the slip-damaged SH1 still closed at Mangamuka Gorge the smash closed the highway for close to three hours, causing traffic to back up for more than a kilometre.
The vehicles involved, a Holden Rodeo ute and a light Toyota truck from a Northland rental company, came to rest about 100m apart in the ditch next to the southbound lane.
Both drivers were trapped and had to be cut out of their cabs by volunteer firefighters using hydraulic cutting equipment.
Two helicopters from the Northland Emergency Services Trust landed in a nearby paddock and flew the men to Whangārei Hospital. Their condition was described as serious.
Constable Ray Iwashita, of Mid North police, said one of the vehicles had crossed the centre line. While the investigation was still in its early stages he would not say which driver appeared to be at fault.
It was not yet known whether speed or alcohol were factors.
Both vehicles had just one occupant.
Traffic started flowing, one lane at a time, about 9.30am.
Specialist investigators from the police Serious Crash Unit and the Commercial Vehicle Investigation Unit attended.
The impact tore off the ute's front-right wheel and left debris scattered over a 200m stretch of highway. It occurred on a fairly straight section of road but near the crest of a small hill.
Two St John ambulances attended along with firefighters from Kaeo, Kerikeri and Mangonui.