Kaitāia Volunteer Fire Brigade senior station officer Colin Kitchen confirmed the two vehicles, a people mover and a Forester, collided just up a hill at Pamapuria.
He said four adults and four children, including two babies, were involved in the crash.
The trapped female driver of the people mover died while being extricated, while three others were flown to Whangārei Hospital.
Kitchen said one vehicle ended up on its roof in a drain, while another was on the other side of the drain.
Crews from the Kaitāia Fire Brigade were still at the scene at 8.15pm while an undertaker arrived to take the body away.
Kitchen described the scene as quite traumatic, given the number of people injured. The rain was pouring when firefighters arrived, he said.
The woman's death will be referred to the Coroner.
Police closed the road to motorists while the Serious Crash Unit carried out a scene examination.
Less than two hours later a second person died after a head-on crash involving two cars towing trailers on SH1 north of Ōkaihau just after 7pm.
The driver of one car was killed and the two occupants of the second car were both moderately injured.
Firefighters from Kerikeri attended the fatal crash.
The road was closed in both directions as the Serious Crash Unit was notified but held up by the first fatal collision in Kaitāia.
Emergency services also attended a third crash on Thursday night. One vehicle was involved in the crash on Roma Rd in Ahipara around 6.30pm.
The two occupants were moderately hurt, police confirmed.
Three road deaths have occurred in Northland for the month of June, taking the year's tally to 15.
On Tuesday afternoon, a driver of a parked car in Taipa narrowly avoided death when a ute ploughed into his vehicle.
Senior constable Warren Bunn of the Serious Crash Unit said that had the man had time to undo his seatbelt the collision could have been a double fatality.
The driver of the ute was killed in the crash on State Highway 10 near the Z service station just after 3pm.
Bunn said the ute had been "travelling at some speed for some reason". The investigation is ongoing.
Police have advised motorists to take extra care on the road this long weekend.
