The Tongariro Alpine Crossing may be fully open to walkers by summer if volcanic activity on Mt Tongariro continued to decrease and the hazard zone around the eruption area reduced, the Conservation Department says.

The popular 19-kilometre track will be partially open to walkers from Mangatepopo Rd entrance to Red Crater this weekend.

Restricted public access to the track, and the Northern Tongariro Circuit, have been eased by DOC after alert levels were lowered and the hazard zone around Te Maari craters was decreased to a three kilometre radius.

Conservation Department manager Nic Peet said public access on the popular tracks would be increased as the high risk area was reduced further.

Access from Mangatepopo Rd to Red Crater, and Waihonunu Hut to Oturere Hut will be open from Saturday, said Mr Peet. However access from Oturere Hut to Red Crater, and Red Crater to Ketetahi Rd will remained closed.

It is unlikely the Tongariro Alpine Crossing will be fully open until the hazard zone is safe to enter and damaged tracks and facilities are repaired, he said.

“If the current inactivity continues and the high risk area is further reduced the Tongariro Alpine Crossing will be open before the summer tramping season starts."

All other facilities, activities and alternative walking tracks are fully operational within the Tongariro National Park.

Mt Tongariro guardians Ngati Hikairo placed a rahui, or protective restriction,  in the high-risk area to ensure public safety on all tracks within the hazard zone.

A blessing to re-open the track will be held at the Mangatepopo Rd entrance by Ngati Hikairo on Friday.

- © Fairfax NZ News