Park Alert

Ferries to Georges Island are suspended through Wednesday, June 26, due to waterline repairs. Ferries to Spectacle Island and Peddocks Island will operate on the regular summer season schedule.

Cathleen Stone Island

Travel to Cathleen Stone Island and discover how its education center is impacting the lives of students.

A beautiful destination to visit, Cathleen Stone Island (formerly known as Thompson Island) is perfect for exploring nature thanks to its salt marshes, herons, egrets, flowering meadows, and fruit trees. Prior to the development of Boston, the island functioned as a trading post between Native Americans and David Thompson. The island later became a farm and trade school for orphans from 1833 to 1975. Today, the island is home to Cathleen Stone Island Outward Bound, a non-profit education organization offering programs in leadership, environmental education, and youth empowerment.

Perfect for any outdoor event, including weddings and company outings, Cathleen Stone Island returns proceeds from private events to its education center. Plan a company outing, or enjoy a relaxing nature walk, during your next visit! Please note that public ferry service to the island is available only on weekends during the spring and summer months.

Public Access

Cathleen Stone Island has been an educational institution since 1833. It is privately owned and protected by a Conservation Restriction by Massachusetts Department of Conservation and Recreation (DCR) and the National Park Service (NPS). The conservation restriction conserves natural and historic resources and ensures opportunities for public access.

  • Public visitors are welcome to the Conservation Area, but not the Building Envelope, by scheduled ferry (see map)

To find out about Cathleen Stone Island Outward Bound programs and events, go to

How to visit Thompson Island:

NOTE: Pedestrian beach access for fishing, fowling, or navigation is permitted by Massachusetts Colonial ordinance year-round via the sandbar (or ‘spit’) from Quincy Squaw Rock Park, and in accordance with state fishing and hunting laws and regulations.

  • CAUTION – The ‘spit’ area is underwater at high tide. Currents and shifting sand can be dangerous. Consult tide charts. Pass at your own risk
Thompson Marsh Dan Squire Amenities


  • Restrooms
  • Drinking Water
  • Hiking Trails
  • Picnic Areas
  • Event Tent
Thompson Marsh Exploration Dan Squire Activities

Recreation & Activities

  • Picnicking
  • Hiking
  • Tidepooling
  • Bird watching
Park Rangers

Know Before You Go

  • Ferries to Thompson Island are on Saturdays and Sundays only. Ferries leave from the EDIC pier in South Boston. Tickets must be reserved in advance. Click here to learn more about ferry access.
  • Private boaters may access the beach area only year round. Building access is limited to public restroom use only.  Dogs are permitted on beach Sept 15 – April 1.
  • The spit between Thompson Island and Quincy is submerged at high tide. Consult tide charts and use extreme caution if traveling across the spit.

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