The state Department of Natural Resources has announced plans to sell mineral leases under 103,000 acres of land in northeast Minnesota.

The lease sale this fall would allow mining companies to explore for nonferrous minerals like copper and nickel. The operations also could look for precious metals like platinum and gold on land in seven counties, largely outside traditional mining areas.

The mineral leases will be the state's first since 2012, when a group of landowners argued they should be subject to environmental review.

But the plan marks the first time the agency is actively seeking public input on a mineral lease sale, said Jess Richards, the DNR's director of lands and minerals.

"Following the 2012 mineral lease sale, we went through a series of steps where we redesigned the process to ensure that it's more transparent and that there's opportunities for public input into the process," Richards said.

The largest potential area available for leases covers about 47,000 acres in and around the Cloquet Valley State Forest about 30 miles north of Duluth. The DNR previously identified large concentrations of platinum there.

That worries environmentalists because much of that area has a sensitive ecosystem and drains into the Cloquet River, which eventually drains into Lake Superior, said Kristin Larsen, founder of Friends of the Cloquet Valley State Forest.

"You can go 20 miles north and be in a very, very wild place, so this is something that I think the people of Duluth should be aware of," said Larsen, who lives about two miles from one of the proposed leasing sites. "This would be a major change to our region, if this were mined."

State mineral leases are auctioned off every year or two to mining companies interested in exploring for valuable deposits. The latest one will be Minnesota's 34th metallic minerals lease sale. Historically they were often granted with little fanfare.

Only about 2 percent of leases sold in the last 50 years have resulted in exploratory drilling, DNR officials say.

But the prospects of copper-nickel mining, including the nearly completed environmental review of the proposed PolyMet Mining project, have ramped up the level of public scrutiny.

In past years, landowners have complained that the state granted mineral rightsexploration leases on private property. While the mineral rights are state owned, about 6 percent of the 103,000 acres up for possible lease this year are on private property, Richards said.

Others have argued for environmental review of exploration leases before they are awarded to mining companies. The Minnesota Court of Appeals ruled in 2013 thatenvironmental review should only be conducted when a company proposes a specific exploration project.

The DNR is charged with managing state-owned minerals for exploration and development. According to the agency, mining companies pay annual rent of $60 to $1,000 per parcel for the first two years, an amount that increases over time. Last year, nonferrous mineral lease rentals generated about $1.1 million for the state.

Even if leases are awarded this fall, Richards said, that doesn't guarantee there will be drilling. They ultimately would have to be approved by the state Executive Council, which includes the governor, lieutenant governor, auditor, attorney general and secretary of state.

"A lease doesn't automatically mean drilling, and it certainly doesn't automatically mean mining," he said. "But we're very interested in getting input from folks so that we can make sure we're considering these areas properly."�