Why is Silver Bay's Black Beach a Lake Superior tourist destination, but Michigan's "stamp sands" a Superfund site?

Why is Silver Bay's Black Beach a Lake Superior tourist destination, but Michigan's "stamp sands" a Superfund site?

Mining operations left behind uniquely colored beaches in Minnesota’s Silver Bay and Michigan’s Gay. But the materials are different.

Mining created these Lake Superior black sand beaches. One’s a tourist destination, the other a Superfund site. - Great Lakes Commission

Mining operations left behind uniquely colored beaches in Minnesota and Michigan, but the materials are different. Minnesota’s Black Beach in Silver Bay contains stamp sands from taconite tailings and is a popular tourist area. About 100 miles away in the town of Gay, Michigan, copper tailings have created a Superfund site. Read the full story by The Minnesota Star Tribune.