The Fire Service says it will be fighting fires in the Waipoua forest for several days.
The fires broke out about 7.30pm on Thursday.
About 20 hectares are still burning in a pine plantation, north of Dargaville on Friday.
Six fire appliances, two helicopters and bulldozers are being used.
The forest is home to New Zealand's largest living kauri, Tane Mahuta.
