The Boston Harbor Islands contain 30 islands (some former islands) ranging in size of less than an acre to 214 acres. Many of the islands are drumlins (glacier-formed, asymmetrical, elongated masses) forming sloped hills or bedrock outcroppings. Together, they total 1600 acres or over 50 square miles.
In 1996, Congress established the Boston Harbor Islands as a National Recreation Area as part of the National Park Service. The park includes 16 islands of the Boston Harbor Islands State Park established in the 1970s. This national park is unusual because the federal government does not own it. State and municipal agencies or private non-profit organizations independently own islands.
The Boston Harbor Island Partnership is a 13-member body created to coordinate the activities of federal, state and local authorities along with the private sector in the development and implementation of a general management plan. Representation on the partnership includes: