New Zealand's Environment Court has cleared the way for Bathurst Resources to mine for coal on the West Coast's Denniston Plateau.
Thursday's ruling allows Bathurst Resources to run an open cast mine on the plateau near Westport and follows a series of failed legal challenges by conservationists.
The government in May granted the company the access to conservation land that it needs to start mining.
Ministers, at the time, said it would create 225 jobs and would be worth about $NZ100 million ($A89.44 million) a year to local suppliers and contractors.
The NZ Green Party says the court ruling is a disaster.
"The Denniston Plateau isn't just any old piece of conservation estate," said mining spokeswoman Catherine Delahunty.
"Its sandstone plateau ecosystem is home to bonsai gardens of rata, tussock and pigmy pine, it is home to great spotted kiwi, carnivorous giant snails and green geckos."
Ms Delahunty says the government had been determined to allow an open cast mine from the outset, no matter what the environmental cost.
"Prime Minister John Key has publicly backed Bathurst Resources and opened their Wellington headquarters in 2012," she said.
"The government is ripping open this rare and stunning landscape for coal mining - it's simply immoral."
The court's ruling says consent will be granted subject to final "minor drafting" of the conditions around the application.
Bathurst plans eventually to take as much as four million tonnes a year of the high grade coking coal, used in steel-making, from the Buller coal fields, with the Escarpment mine being the first of several planned.
