It was the earliest of three dams on the river in today 's Rockland County that supported milling operations ; today it is the only one that remains mostly intact .
The mill shut down after a mid-20th century fire .
It was the earliest of three dams on the river in today 's Rockland County that supported milling operations ; today it is the only one that remains mostly intact , although the mill shut down after a mid-20th century fire .