Iwi will have equal say with the Crown in managing Taranaki Maunga and the national park, as part of redress for the confiscation of the mountain.
A new group called Te Tōpuni Kōkōrangi - half appointed by iwi and half by the Crown - will develop future management plans for Te Papakura o Taranaki (currently Egmont National Park).
Plans will then need joint approval from both the Minister of Conservation and another group, Te Tōpuni Ngarahu, made up of representatives from the eight iwi of Taranaki.
Co-governance of Taranaki Maunga has been hammered out between the Crown and iwi negotiators.
They agreed in 2017 that the mountain and ranges of the park would become a legal person, Te Kāhui Tupua, which would officially own itself.
Lead negotiator Jamie Tuuta said talks over the past 18 months had worked out how the new law would work, in a Collective Redress Deed.
"The redress is creating a new arrangement to guide aspects relating to the Maunga as a whole… and then what the deed and legislation sets out is how to do that."
He said gaining equal say had been hard-fought.
"The key here is actually giving life to this treaty partnership… the thing we had a whole lot of pushback on is that the management plan is approved by the Minister of Conservation and ngā iwi o Taranaki."
National park planning is normally led by the Department of Conservation (DOC) and conservation boards, with input from Treaty partners, and then approved by the New Zealand Conservation Authority with no Māori decision-making involved.
Te Papakura o Taranaki would remain a national park and DOC retain day-to-day management duties, as iwi were wary of the liability that comes with unfettered public access, which was a Crown bottom line.
But Tuuta said iwi might want to be more hands-on in future as their capacity increased.
"Who knows in five, 10, 15 years' time we might be in a different position, so we're just making sure in these arrangements there are opportunities to further advance particular aspirations the whānau might have."
Negotiator Liana Poutu said funding had also been hard-won, as the Crown insisted financial compensation was final under individual iwi settlements.
But the iwi team argued that resources would be needed to do the work being negotiated.
"We were initially offered nine million… and where we landed was 20 million as a final offer from the Crown."
Poutu said iwi negotiators knew that would not be enough to sustain the work into the future and put the talks on hold.
"We've got a Crown offer and what we've agreed is 35 million dollars… to go along with this package and do all the things set out there."
Mountain confiscated
The mountain was taken in 1865 as part of the confiscation of Māori land for "rebellion" in the Taranaki Wars.
In 1978 the mountain was vested in the Taranaki Māori Trust Board but then immediately gifted back to the nation. The Waitangi Tribunal found little evidence that hapū had agreed to the switch.
Poutu said Te Tōpuni Ngarahu would carry out collective legal responsibilities of iwi and appoint half of Te Tōpuni Kōkōrangi, which would act as the face and voice of the legal personality of the maunga.
Tuuta said that although the Crown would appoint the other half of Te Tōpuni Kōkōrangi, all the members would be there to act on behalf of Te Kāhui Tupua - the mountain and ranges.
He said the members must have knowledge of iwi values and relationships with Taranaki Maunga including its status as an ancestor, so Crown appointees might also be Māori.
Final details of the Collective Redress Deed were being ironed out and it would likely be initialled early next month.
The Deed would then go out to iwi for ratification by October, before a signing event in December, and the introduction of the Bill to Parliament in March next year.
Local Democracy Reporting is a public interest news service supported by RNZ, the News Publishers' Association and NZ On Air.