The Minnesota Department of Natural Resources (DNR) has fumbled away an opportunity to free up the sweeping study kept secret by the Trump administration of copper mining's risks to the Boundary Waters Canoe Area Wilderness watershed.

The misstep undermines the strong message from state officials last November that they "expect to have access" to the research kept under wraps now for almost two years.

At issue is a June 9 decision by the DNR to authorize temporary access to 680 acres of state land to Twin Metals Minnesota. Owned by Chilean mining giant Antofagasta, it is one of several companies aiming to eventually mine the rich deposits of copper, nickel and other precious metals in northeast Minnesota.

Unlike PolyMet, another well-known copper mining project in the region, Twin Metals' operations would lie within the BWCA watershed.

Twin Metals' underground mine and accompanying aboveground operations would not be within the federally protected preserve. But its site is within a few miles of it and borders a reservoir that flows north into the watery wilderness's fragile ecosystem.

That location, and the different risks copper mining poses vs. iron mining, is why the Star Tribune Editorial Board opposed the Twin Metals project in November's "Not this mine. Not this location" special report.

To be clear, the DNR land-access decision doesn't approve the project. It just allows Twin Metals to conduct environmental evaluation of state land near the mine site. The company is eyeing the parcel as a site for tailings storage. Granting access for exploration and surveys is a very small step in what will be a yearslong permitting process.

The decision is nevertheless problematic. Federal officials have blown off congressional requests, not to mention Freedom of Information Act requests from the Editorial Board and others, to see data gathered during an almost-completed, two-year U.S. Forest Service study of copper mining's risks to the BWCA. Nor has the state had access, which is stunning given its substantial role in permitting.

The best hope to release the data at this point is the state wielding its leverage. The Editorial Board has repeatedly urged the state to halt its work on Twin Metals until the feds free the scientific analysis. The land access recently granted is an example of activity the state could have suspended.

The DNR defended the decision in a statement this week. The action was taken "solely to facilitate the collection of site-specific environmental data needed to evaluate Twin Metals' proposed project. These site-specific data are needed regardless of whether the federal government provides the data they previously generated to assess far more general questions about nonferrous mining throughout the Rainy River Basin." In addition, the agency noted, the "agreement expressly states that no decisions have been made about the future use of state lands."

Asked for a statement, Twin Metals referred an editorial writer to its website, which includes its mine plan of operations.

The DNR's explanation is unsatisfactory and undercuts its own previous good work. Last fall, in an announcement coinciding with the editorial special report, the agency admirably announced that it would conduct a state-level environmental impact statement. As part of that, the agency made it clear it expected access to all prepared federal data.

The data, however, still hasn't been shared with the state. That's unlikely to change. Industry-friendly officials lead key federal environmental agencies, and the Trump administration has made regulatory rollbacks a priority. A different state agency, the Minnesota Pollution Control Agency, has warned that federal changes to water-quality protections would "kneecap" state regulators' authority to protect waterways.

Greenlighting even a small step forward for Twin Metals sends the "totally wrong signal on this project when the state has the ability and authority to say, wait a minute, we can't move forward until we get this fundamental information" from the feds, said Tom Landwehr. He is a former DNR commissioner who now leads the Campaign to Save the Boundary Waters, which opposes the Twin Metals project.

Granting the access was a mistake. There will likely be more such requests. The DNR should say no until the feds free the science currently held captive.