Heather Jean Bryham and Linda Bryham live north of the Brynderwyn Hills, where two towering stands of kahikatea trees flank State Highway 1 and form a natural gateway to Waipū. The trees are in the path of a proposed new four-lane highway and two roundabouts as part of the Northland Corridor linking Auckland with Whangārei. The sisters said the prospect of losing the land their family has farmed for three generations is "devastating." Their father's ashes are scattered in the forest, which they have maintained for decades, fencing it off from stock and keeping it free of weeds and pests. The stands also contain ancient pūriri trees with girths up to six meters. Earlier this year, NZTA told the family it could eventually require 90 percent of their land, leaving them two small flood-prone areas, one accessible only by kayak. The family has spent around $120,000 over the past five years planting the banks of the Ahuroa River, which flows through the property. While the sisters understand the need for a new route over the slip-prone Brynderwyn Hills, they question why the existing highway over flat land further north cannot be widened. An NZTA spokesperson said the route for the middle section, including the forest, has not yet been officially designated, and no final decisions have been made. The agency normally seeks to acquire land about two years before construction, which could be many years away. Environmental group Forest and Bird has raised concerns about the planned route, which goes through ancient forest home to critically threatened long-tailed bats and vulnerable Hochstetter's frogs. Forest and Bird Northland conservation manager Dean Baigent-Mercer called for a return to an earlier option that went around, not over, the hills.