Historical Marker
All Aboard!
Historical marker location:
510 Thomas Edison Parkway, Port Huron, Michigan
( Marker is at the intersection of Thomas Edison Parkway and the Bluewater Bridge to Sarnia, on the right when traveling south on Thomas Edison Parkway.)
Michigan is the only state to have two designated "state stones": the Petoskey Stone, which is the state stone of Michigan, and the Isle Royale Greenstone, which is the state gemstone of Michigan. The Petoskey Stone is a fossilized coral that is found primarily in the northern Lower Peninsula, while the Isle Royale Greenstone is a rare mineral found only on Isle Royale in Lake Superior.