Mining interests in Minn­esota got a second dose of bad news Tuesday, when federal regulators said they would not immediately renew leases on land near that Boundary Waters Canoe Area that are critical to a copper-nickel mine proposed by Twin Metals Minnesota.

The Bureau of Land Management denied a request by Twin Metals to automatically renew leases that give it access to ore just south of the BWCA on the Kawishiwi River. Instead, the agency said it would begin an environmental review of the potential effect of mining on the region.

That means the leases could be renewed eventually, or the review could trigger any number of regulatory steps.

Still, the long-awaited decision was seen as a victory by environmental groups, which have expressed hope that the federal government will ban mining in the nearly pristine watershed.

The decision followed by a day the unexpected announcement by Gov. Mark Dayton that he opposes mining near the Boundary Waters because of the environmental threats it poses to a place that Minnesotans treasure. He said he would not allow state regulators to give Twin Metals access to state lands for development work.

Last week, PolyMet Mining Corp. won state approval of a 10-year environmental review for its own proposed copper-nickel mine.

PolyMet’s project is about 20 miles to the southeast, in a watershed that drains into Lake Superior, while the Twin Metals watershed drains north toward the BWCA.