From the record
“The Marlborough Historic District is a cement factory located on James Road in Pleasant Plains Township, Michigan. It was designated a Michigan State Historic Site in 1971 and listed on the National Register of Historic Places in 1972.”
Wikipedia article Marlborough Historic District, CC BY-SA 4.0.
One of 4 National Register listings published here for Lake County · listed in 1972 · category: District.
Sources: the Wikipedia article · the case file at the National Archives · the National Register database, National Park Service
