A company whose proposal for a mine near the Boundary Waters Canoe Area Wilderness has been blocked by the federal government now wants to do exploratory drilling at a new site nearby.

The application to the state of Minnesota indicates Twin Metals is still interested in mining in Minnesota, despite the recent setbacks.

Franconia Minerals LLC, a subsidiary of Twin Metals, asked regulators for permission to sink six exploratory holes and search for minerals in a Sept. 22 application. The proposed drill sites are scattered between the former Dunka mine, east of Babbitt, and the eastern edge of Bob Bay, a part of Birch Lake, in St. Louis County.

Like the site near Ely where Twin Metals proposed an underground copper-nickel mine, the area is in the Rainy River watershed, which flows to the protected Boundary Waters.

"Our continued goal is to gain a deeper understanding of Twin Metals' mineral resources and assess our potential to supply critical minerals needed to support Minnesota and our nation in a sustainable transition to a cleaner future," company spokeswoman Kathy Graul wrote in an email.

Nickel has emerged as a crucial metal for many electric vehicle batteries, but only one nickel mine is operating in the United States. The deposit Twin Metals wants to explore contains more copper than nickel, though copper is also important for electricity conduction.

Bruce Johnson, a retired Department of Natural Resources employee who worked as a regulator at the Dunka mine and other nearby locations, said the area has already been polluted by sulfate runoff from the closed taconite site.

"We already know we have a problem on Birch Lake," he said. "To explore something we know we can't control ... why drill it?"

The Department of Natural Resources has 20 days from the date of Twin Metals' application to make a decision, agency spokeswoman Gail Nosek wrote in an email. Unlike a mine, the exploratory holes do not require extensive environmental permitting. If approved, the company could drill through March 2025.

Twin Metals is asking to drill state-owned minerals, Nosek said. That means the land is not affected by a recent mining and exploration ban from the Biden administration, which removed 225,000 acres of federal land and minerals in the Boundary Waters watershed from any form of extraction, including the land where Twin Metals wanted to open its mine.

That decision came after a federal study determined that hardrock mining would inherently risk the environmental quality of the Boundary Waters, a federally-designated wilderness that covers a million acres of streams, lakes and boreal forest.

"Having failed at the federal level, Twin Metals is now searching for ways to open their toxic mine on a state level," Chris Knopf, executive director of the environmental group Friends of the Boundary Waters Wilderness, wrote in an email.

The exploration site is a few miles southwest of the proposed mine and a focus of the company since at least 2010, according to DNR.

Past estimates have suggested the metal deposit in the area is about an eighth of the size of the one Twin Metals previously sought to mine, with roughly 100 million tons of mineable material, said Fred Campbell, a geologist who worked on a state study of hardrock mining in the 1970s. But Campbell said there are indications that this deposit has more rare metals, such as platinum and palladium.

Both sites are part of the Duluth Complex, an underground formation in northeast Minnesota where companies have sought to drill primarily for copper. Further southwest, PolyMet has proposed the NorthMet copper-nickel mine, and the company's partner Teck Resources is also exploring underground next door.

Twin Metals has said in the past it is searching for copper, nickel, cobalt and platinum, Nosek said. Asked how deep the company wanted to drill, she responded that this information wasn't required in an exploration plan.

Twin Metals Minnesota is a wholly owned subsidiary of the Chilean mining giant Antofagasta PLC.