The Bureau of Land Management has extended 13 prospecting permits within the Superior National Forest to Twin Metals, a move that environmental groups are appealing over concerns any exploratory drilling will harm the environment and endangered species.

The extension of the permits, which cover more than 15,000 acres of national forest land near the Boundary Waters Canoe Area Wilderness, were approved by the BLM on May 1 and gives the copper-nickel mining company the exclusive right to explore for minerals with drilling and other methods on that federal land through April 2024. It does not allow the company to mine there.

The prospecting permits all sit outside the area of Twin Metals' proposed underground mine, processing plant and dry-stacked tailings storage area near Birch Lake. In December, the company filed its formal project proposal to regulators for that mine, kicking off a years-long state and federal environmental review process.

Asked if the company was eyeing a larger mine in some of the prospecting permit areas, Twin Metals spokesperson Kathy Graul stressed Twin Metals and its predecessors have held multiple federal, state and private mineral interests in the Duluth Complex for decades.

"In order to advance a prospecting permit, exploration work needs to occur to determine whether a valuable mineral resource exists that could be developed under a mine plan," Graul said in an email. "No determination regarding mining potential has been made on those sites."

Opponents of Twin Metals, owned by Chilean mining conglomerate Antofagasta, have long argued a mine within the same watershed as the BWCAW would environmental risks to the wilderness and say the project could send tainted runoff into the BWCAW. Supporters say the mine would bring much-need jobs to the region.

According to BLM documents, the prospecting permits expired in 2014 and 2015. A Final Environmental Impact Statement for 29 prospecting permits was released in 2012 with the U.S. Forest Service consenting to the BLM issuing the permits. In 2015, the BLM determined the National Environmental Policy Act was adequate for the extension of 13 of those prospecting permits. The permit extension was then approved on May 1, 2020.

But in an appeal filed Wednesday, environmental groups The Wilderness Society, Northeastern Minnesotans for Wilderness and the Center for Biological Diversity, argued the BLM did not consider "new science and information" that has emerged since the 2012 environmental review. In the appeal the groups say the BLM failed to comply with the National Environmental Policy Act, Endangered Species Act and the agency's own regulations.

“Twin Metals’ permits were improperly extended under cover of an unprecedented public health crisis with no public notice or engagement,” Alison Flint, senior legal director at The Wilderness Society, said in a news release. “The move represents another benchmark in the Trump administration’s relentless efforts to fast-track mining that would devastate the Boundary Waters’ abundant clean water and beloved wilderness.”

The BLM declined to comment on the appeal in an email to the News Tribune.

On May 20, the groups notified the BLM that they intend to sue over the decision.