The decision from the Buller District Council will allow mining company Stevenson Limited access to the Reserve for the Te Kuha coal mine project .
Last month the High Court decided that, when the Crown Minerals Act was passed in 1991, it implicitly repealed the protections of the Reserves Act for special features such as native plants and animals, and scenic values.
“We disagree with this decision," West Coast regional manager Jen Miller said.
"In Forest & Bird’s view, the Crown Minerals Act does not override the council’s obligations under the Reserves Act to protect the reserve's natural features.
"The reserve is home to species of threatened birds, lizards and plant species including the great spotted kiwi, the South Island fernbird and the West Coast green gecko."
Miller said she had "absolutely no idea but we wouldn't appeal if we didn't think we had a chance".