U.S. District Judge Trevor McFadden ruled the U.S. Department of the Interior acted within its “inherent reconsideration authority,” and did nothing wrong in resurrecting the Twin Metals’ leases for its proposed mine in Minnesota.

The Star Tribune reported that the Obama administration had previously denied the company’s request to renew its two leases to mine on 5,000 acres of public land in Superior National Forest after the U.S. Forest Service concluded that copper mining so close to the Boundary Waters was too risky, and it could cause “serious and irreparable harm” to an “irreplaceable wilderness area.”

“Here, Interior timely corrected an error that would have deprived Twin Metals of its right to valuable leases,” McFadden wrote in the ruling.

The decision is a key moment in the legal and political battle over opening up Minnesota to copper and nickel mining proposed by Twin Metals and PolyMet.

For Twin Metals Minnesota, a subsidiary of Chilean copper mining giant Antofagasta, McFadden’s decision was a crucial step.

The company plans to extract 16 kt/d (20,000 stpd) from the huge underground copper-nickel mine it wants to build just outside the Boundary Waters near Birch Lake. It submitted its official plan to state and federal regulators in December. The Twin Metals project is one of two fiercely debated copper-nickel mines proposed for northeast Minnesota.

“We’re very gratified that this decision – a summary judgment – validates our contention that the decision to cancel leases held in good standing for more than 50 years was arbitrary and wrong,” said Kelly Osborne, chief executive officer of Twin Metals. “Companies must be able to trust the regulatory process in order to risk the enormous capital required to extract metals such as copper, nickel, cobalt and platinum group metals that are vital to creation of the green economy our world so desperately needs.”

The two leases were issued in 1966 to a Twin Metals predecessor company and renewed twice, in 1989 and again in 2004. When Twin Metals applied for a third renewal in 2012, the Interior Department ultimately said no in 2016, based on objections from the U.S. Forest Service. In May of 2017, the Interior Department’s top legal official, Daniel Jorjani, ruled that the earlier lease cancellation was erroneous on grounds that Forest Service approval was not a condition of the lease renewal and that the leases’ renewal was required under the terms they were granted. The Interior Department reinstated the leases, which were formally renewed in May of 2019.

Opponents of the mine said they would appeal. They said the plain language in the leases meant that Twin Metals was not entitled to an automatic lease renewal.