COPEMISH, Mich. (AP) — State wildlife officials have confiscated a 93-pound Petoskey boulder from a man who pulled it out of Lake Michigan.

The Grand Rapids Press reports Thursday Department of Natural Resources officers went to Tim O’Brien’s home in the Manistee County community of Copemish the day before. They collected the large rock he found in September near Northport, lugged to shore and took home.

Michigan law prohibits removing more than 25 pounds of rocks or minerals annually from state-owned lands, including Great Lakes bottomlands.

O’Brien says he wasn’t aware of the ordinance and only planned to display it on his lawn. DNR spokesman Ed Golder says O’Brien cooperated during the investigation.

The Petoskey stone is Michigan’s state stone. It’s considered a fossilized coral. When wet or polished, a distinctive pattern emerges.

Information from: The Grand Rapids Press, http://www.mlive.com/grand-rapids