Slate Island

View from Slate Island looking towards Hingham

NPS Photo

Quick Facts

Location:

Boston Harbor

MANAGED BY:

Massachusetts Department of Conservation and Recreation

One of the smallest islands in the harbor at just 12.5 upland acres, Slate Island consists of slate outcroppings that are covered in glacial till. Like other islands in the harbor, Indigenous people accessed the island seasonally for thousands of years before European colonization.  

Slate Island's name comes from the presence of slate on the island. In 1631, the government ordered that no quarrying could occur without permission from the colony's general court. William Torey received a grant for the island in 1650, with a stipulation that "any man shall be free to make use of the slate." Soon after, the town of Hull took ownership of the island.  

In the 1800s a hermit lived in a hut, near the southern cove. In the 1890s, owner Edwin Clapp deeded the island to Clapp Memorial Association. The association hosted summer camps on the island in 1937, but it closed the following summer due to lack of sanitary facilities. In the 1970s, the island became a part of Boston Harbor Islands State Park.¹

Learn More...

Island Facts: Slate Island - Boston Harbor Islands National Recreation Area (U.S. National Park Service) (nps.gov)

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Footnotes 

1. Moses Foster Sweetser, King's Handbook of Boston Harbor (Cambridge, MA: Moses King, 1883), 189; Olmsted Center for Landscape Preservation, Cultural Landscape Report: Boston Harbor Islands National & State Park, Volume 2: Existing Conditions (Boston: National Park Service, 2017), 235-238.