Kaitāia and Ahipara firefighters remained at the scene, and police confirmed at 12.15pm the road remained closed.
The crash is in Pukepoto, near the intersection with Tangonge Rd. Photo / Google Maps
Hato Hone St John sent a helicopter, two ambulances and a manager to treat the three patients.
One person in a critical condition and one in a moderate condition were transported to Whangārei Hospital, while one patient with minor injuries was treated at the scene.
Kaitaia-Awaroa Rd is the main road between Kaitāia and Ahipara, with an alternative route available through Gill Rd in Awanui and Sandhills Rd.
The road closure is near Te Uri o Hina Marae and Te Rarawa Marae.
Serious injuries in Waipu motorcycle crash
Meanwhile, State Highway 1 at Waipu was restricted to one lane for a time after a motorcycle crash.
Police said the single-vehicle crash happened between Finlayson Brook Rd and Waipu Bypass about 11.30am.
One person was taken to hospital in a serious condition.
The busy highway was down to one lane for about 45 minutes, with police saying at 12.15pm that it was due to reopen.
People took to social media to report major traffic delays in the area at the time of the crash.
Denise Piper is a news reporter for the Northern Advocate, focusing on health and business. She has more than 20 years in journalism and is passionate about covering stories that make a difference.