The 25-acre Icelandite Coastal Fen Scientific and Natural Area along the North Shore of Lake Superior protects a rare coastal wetland and a unique kind of volcanic rock.

After more than a quarter century of effort, the Minnesota Department of Natural Resources has protected a rare wetland with unusual geologic features as part of the state’s newest nature preserve.

The 25-acre Icelandite Coastal Fen Scientific and Natural Area, located 11 miles northeast of Grand Marais, preserves one of only two known fens on Lake Superior’s North Shore. A fen is a rare wetland fed by slow-moving groundwater, made up of a thick layer of peat.

“We don’t have anything like it protected in the state,” said Judy Elbert, SNA program supervisor for the Minnesota DNR. “The SNA is truly unique, for both its ecological and geological features.”

The site features a volcanic lava rock called icelandite, which is rare in the Midwest. It’s a lighter gray than the dark basalt more typically found on the North Shore. Both kinds of rock are about 1.1 billion years old.