Grindstone Island Map

Grindstone Island is the fourth largest of the Thousand Islands in the St. Lawrence River and the second largest of the American islands in the St. Lawrence. The island lies near Lake Ontario and is part of the United States. In particular, the island is part of the Town of Clayton in Jefferson County, New York.
  • Location: St. Lawrence River
  • Length: 5 mi (8 km)
  • Width: 3 mi (5 km)
  • Highest elevation: 285 ft (86.9 m)
  • State: New York
  • County: Jefferson
  • Town: Clayton
Data from: en.wikipedia.org