Transit New Zealand is facing opposition to the felling of 250 trees, including rimu and matai, on the west coast of the South Island.
The trees are being removed from a stretch of State Highway 6 in the Haast Valley, which runs alongside a World Heritage site.
The Royal Forest & Bird Society claims healthy trees are among those affected. The Green Party has called the operation a chainsaw massacre.
Transit says the trees are being removed because they pose a threat to road users.
It says permission from the Department of Conservation was obtained before any trees were felled.