A District Court judge granted a preliminary injunction in a case seeking to block the land transfer.
The decision comes after a proposed land sale of the former Anaconda copper mine by the Bureau of Land Management to the Atlantic Richfield Company for the price of zero dollars.
Earlier this week, a coalition of tribal and environmental groups who oppose the sale argued in court that it would allow mining to begin again, without public input.
Lawyers for the company and the Bureau of Land Management say the transfer would help get it cleaned up faster.
Nearby communities said they already see high rates of cancers due to contamination at the now-closed mine. Members of Indigenous non-profits also stated that the land sale would further restrict access to historically religiously significant sites.
The court found the privatization of the sale of public lands would cause irreparable harm to communities who continue to use it for recreational, religious, and other purposes.
The ruling is just the first step in what’s likely to be a long legal battle over the future of the site and who gets a say in what happens to it.