Governor-General Dame Patsy Reddy returned Pukaha Mount Bruce to the Rangitāne people on Saturday.
The return of the land (942 hectares), on which Pukaha National Wildlife Centre is situated, is part of a $32 million Treaty of Waitangi settlement achieved in 2016.
The agreement is the second-largest Treaty settlement in terms of the geographic area covered.
In 2016, Treaty Settlements Minister Chris Finlayson said Rangitāne was left virtually landless by the early 20th century and the iwi struggled to maintain its distinct identity, customary knowledge and language.
Dame Patsy said it was a significant and emotional occasion.
"This new chapter for Rangitāne has offered some valuable opportunities for you to work together," she said.
"We are all guardians of the land and we share a responsibility to protect our wildlife and our native bush. Pukaha is the last [significant] remnant of the 70-Mile Bush which stretched from Wairarapa to Central Hawke's Bay. It is a taonga which reminds us of what has been lost.
"Today, Pukaha Wildlife Centre has enormous conservation importance for all of Aotearoa New Zealand and is a symbol of what can be regained. It is back with Rangitāne where it belongs.
"Rangitāne's decision to gift Pukaha to New Zealand in a year's time shows generosity and foresight."
Prime Minister Jacinda Ardern said at Pukaha last November that she named the kiwi about to hatch Koha Te Aroha (gift of love) because it was an "incredibly generous gift to the nation" by the iwi to gift the land back.
As the Queen's representative, Dame Patsy wore a korowai (feather cloak) not worn before while she spoke to hand over the land. It was made by Rose Bittle and took three years to make.
"I'm delighted to feel the aroha that has been woven into it before it is gifted to Pukaha to be displayed," she said.
Talking about the land that stretched from the sea to the mountains "it was one, we were one", said Mavis Mullins, chairwoman of Rangitāne o Tamaki nui a Rua.
"Then, we had boundaries and districts and regions and councils and we became split.
"The start of the settlement process with Tamaki nui a Rua and Wairarapa was a beautiful thing, but it was the right thing. And we started to weave together again that oneness."