Protesters gathered today at Mt Messenger in northern Taranaki to try to stop the construction of a bypass.
Three diggers were airlifted to the remote area to allow work to start on the northern anchor point of a cableway.
Waka Kotahi Transport Agency said the bypass will provide a safer, more resilient route between Taranaki and Waikato while enhancing biodiversity.
But a rangatira of the local Poutama hapū Ngāti Wai kaitiaki Haumoana White said the move is totally wrong and must stop.
He said the mana whenua did not agree to the destruction of the maunga and the valley, which will damage the wetlands and biodiversity.
Izzy De Boam, one of the protesters, said the move is not good for the environment.
She said, "It is well known that the destruction of unique wetlands and pristine native forest is totally unacceptable in 2022. There is an alternative option that is far less damaging and much cheaper which must be adopted."
De Boam said upgrading the current route is a better option.
In 2021, RNZ reported on documents that showed the transport agency and Heritage New Zealand had sidelined Ngā Hapū o Poutama over the building of the passing lane on State Highway 3 in Taranaki.