It forms the southern limit of Thunder Bay and helps define the harbor of Alpena , Michigan .
Scarecrow Island is a small , 7 - acre ( 0.03 - km2 ) island in Lake Huron .
Scarecrow Island forms the southern limit of Thunder Bay and helps define the harbor of Alpena , Michigan .
Scarecrow Island is a small , 7 - acre ( 0.03 - km2 ) island in Lake Huron .