Alpena is situated in northern Michigan, on the shores of Thunder Bay in Lake Huron. It is the largest town in this sparsely populated region. Tourism dominates the summer economy with population numbers swelling. The limestone quarry is an attraction with its bat cave, fossils and limestone formations. The quarry is also the reason why the world's largest cement factory was established in Alpena. A related industry is the manufacture of machinery used to make concrete blocks. Thunder Bay is renowned for its unpredictable weather which has been responsible for over 200 shipwrecks. The area has been declared a marine sanctuary.

Thunder Bay National Marine Sanctuary

© Thunder Bay National Marine Sanctuary

Rockport State Recreation Area

© kitty45/stock.adobe.com