Minnesota regulators have asked the Trump administration to provide the research from an aborted federal study about the impacts of copper mining on the Superior National Forest and its Boundary Waters Canoe Area Wilderness, within 30 days.

The federal study and its materials have been kept secret in defiance of multiple demands for their release, including from U.S. Rep. Betty McCollum, D-Minn., chairwoman of a key funding subcommittee.

The U.S. Department of Agriculture abruptly canceled the Forest Service study in September 2018, after nearly two years of work, saying the analysis "did not reveal new scientific information" and was a "roadblock" to minerals exploration in the Rainy River Watershed.

What has been made public — 60 pages of redaction, with blacked-out pages that say "deliberative process privilege" in red — was released to the Wilderness Society only after it sued.

Department of Natural Resources (DNR) Commissioner Sarah Strommen requested the unreleased research in a March 10 letter to Bob Lueckel, regional head of the U.S. Forest Service in Milwaukee.

Strommen asked for "all previously prepared environmental review data and studies related to the previously proposed federal mineral withdrawal project within the Superior National Forest." That includes information on mineral resources, economic impacts and impacts to the water and wilderness and cultural areas.

The DNR "has a responsibility" to access the research, Strommen wrote, since it's charged with doing an in-depth environmental review of the copper-nickel mine plan that Twin Metals Minnesota has submitted to regulators.

The DNR stated back in 2017 that the U.S. Forest Service study would have "important implications for the people of Minnesota," Strommen wrote. "This remains equally true today."

The move came about four months after the Interior Department reinstated two Twin Metals mineral leases that the Obama administration refused to renew due to the threat of polluting the Boundary Waters. On Tuesday, a federal judge upheld Interior's decision to reinstate the leases.

The DNR declined to discuss the letter on Wednesday.

Alison Flint, senior legal director for the Wilderness Society, said she doesn't know whether Strommen has any greater authority to force disclosure, but is "glad others are continuing to push."

"The bigger picture here is that the Trump administration has gone to the ends of the Earth to keep the study and the taxpayer-funded research that went into it secret from the public," Flint said.

McCollum said that key decisionmakers are being denied access to critical data.

"How can the DNR make any decisions related to this sulfide-ore copper mining project when the best available science has been buried?" she asked.

The nixed study has been a flash point in the fight over opening up Minnesota to nonferrous mining for precious metals. Hard rock mining carries far greater pollution risks than mining for taconite or iron ore because of the toxic sulfide and heavy metals the process produces.

Conservationists say that's too big a threat to the Boundary Waters, a 1.1 million-acre expanse of lakes, boreal forests and streams. A recent Star Tribune/MPR News Minnesota Poll showed that 60% of Minnesotans oppose building new mines near the Boundary Waters.

Nonetheless there is strong support for copper mining on the Iron Range because of the region's mining history, and the desperate need for well-paying, year-round jobs. The outdoor recreation industry isn't a substitute, residents say.

Ely native Becky Rom, national chairwoman of the Campaign to Save the Boundary Waters, said Strommen was "right on."

"Our view was that the state should not proceed with an environmental review until it receives all the information," Rom said.

Twin Metals is a subsidiary of Antofagasta in Chile, one of the world's largest producers of copper.

The underground mine it wants to build just outside the Boundary Waters near Birch Lake would produce about 20,000 tons of ore a day and create about 700 full-time jobs.

Jennifer Bjorhus • 612-673-4683