Firefighters worked on the ground while six choppers attacked the Onerahi fire from the air.
It was a day of fires and destruction in Northland with three houses fully gutted by blazes on Saturday, a garage fire endangering two nearby houses and a small fire in a bakery.
An air and ground assault was launched against a 20 hectare fire in cleared pine forest near the Whangārei suburb of Onerahi, also on Saturday.
A neighbour of the property where the fire started said it was sparked by a bullet ricocheting off a steel plate around 2.30pm on Saturday.
Six helicopters were needed to dump monsoon buckets on the blaze - first two choppers then four more called in to contain it.
Crews from Onerahi, Whangārei, Kamo and Kawakawa fought the fire from the ground, accessing the scene from the end of Cartwright Rd and a paper road off Waikaraka Rd.
The choppers were grounded at about 8.15pm when it became too dark for them to safely operate but two were back in the air all day yesterday extinguishing small outbreaks and smouldering hot spots on the steep land.
A fire crew had stayed at the scene overnight to monitor the situation and shut down hot spots they were able to reach.
Owner of an adjacent property, the Heads Up Adventure Park, Warren Gill said the scrub and pine block was on private land, the owner of which lived in Auckland.
He said the blaze was started by the spark from a bullet hitting a steel plate when another neighbour was shooting at targets.
''It began as a small fire on this dry material and it grew real quick and ran up the side of the hill,'' Gill said.
He said he was not worried about his place during the fire because there was a big creek between it and his place.
However, despite several customers enjoying the park's bike and scooter trails, paint balling and the thrill of a large bushfire at the time, he and his wife Angela called them in, sent them home and closed the park.
Onerahi was blanketed by ash from mid-afternoon on Saturday with people in the quiet suburb's residential streets also reporting burning embers landing on their properties.
The fire's heavy pall of dark smoke could be seen from many other suburbs.
The first house fire of the day was on Houhora Heads Rd, where a house was fully ablaze before fire crews from Houhora and Kaitaia could get there.
The house was burned to the ground. No-one was hurt, and the fire was not suspicious, a fire spokesman said.
A house in McClelland Rd at Whakapara, 28 km north of Whangārei, also burned to the ground after being fully involved by the time fire crews were called at 11.14am.
Fire crews from Hikurangi, Kamo, Kawakawa and Whangārei attended. No one was in the house at the time.
The third house fire of the day was at Matauwhi Rd, Russell, where a small bungalow was destroyed in a blaze which started around 8pm.
Appliances attended from Russell, Paihia and Kawakawa. It is understood no one was in the rental house at the time.
At around the same time, firefighters from Dargaville and Ruawai were battling a garage fire on a property in Hokianga Rd, Dargaville. The 10 square metre garage was destroyed but two very close houses undamaged.
The last fire of the day for Northland's firefighters was a small one inside a bakery in Maunu Rd in Whangārei at 10.20pm. The building was not badly damaged.
A fire investigation officer was to look into the causes of all the fires apart from the Houhora one.