From the record
“The Martin Reef Light Station is a lighthouse located in northern Lake Huron, 4.3 miles (6.9 km) south of Cadogan Point in Clark Township, Michigan. It was listed on the National Register of Historic Places in 2005.”
Wikipedia article Martin Reef Light Station, CC BY-SA 4.0.
One of 22 National Register listings published here for Mackinac County · listed in 2005 · category: Structure.
Sources: the Wikipedia article · the case file at the National Archives · the National Register database, National Park Service