Charles Island


Milford, CT

Anchor Site(s)

Charles Island Natural Area Preserve (managed by CTDEEP as part of Silver Sands State Park)

About the Site

Charles Island Natural Area Preserve, designated a Natural Area Preserve by the State of Connecticut in 1999, is a small densely wooded island important to Connecticut’s waterbirds. Geologically it is a coastal moraine segment, formed by an unsorted glacial deposit (a mixture of rocks and sediment).  It is also a “tied island,” tied to the mainland by a  connecting bar or tie bar consisting of pebbles and cobble. This 14-acre site hosts one of the state’s largest remaining breeding colonies of heron and egret. Designated an Important Bird Area by the National Audubon Society, it provides nesting habitat for rare bird species, including great and snowy egret, long-eared owl, and least tern. Over time, plans for the island have included a tobacco plantation in 1657, a fertilizer plant, a hotel in the 1880s, and a Catholic men’s retreat center in the 1920s and 1930s. All eventually failed, leaving only a few remains of the retreat center.

Ecological Importance
  • Audubon designated Charles Island an Important Bird Area because it supports state-threatened species, including snowy egret and glossy ibis as well as year-round and migratory waterfowl and wading birds.
  • Charles Island was designated a Natural Area Preserve by the state in 1999 due in part to supporting populations of state-threatened snowy egrets and endangered roseate terns.
Recreational Opportunities
  • Open for passive recreation from September to April only.
  • Bring your binoculars to identify rare shorebirds, wading birds and raptors!
Dive Deeper

Audubon Connecticut
Audubon Connecticut’s website provides a detailed look at Charles Island and nearby Silver Sands State Park, including historical records of rare bird populations using these properties

Places to Visit
  • Silver Sands State Park, once the site of a municipal landfill, was designated a State Park in 1960. But its development as a park began in the late 1990s. It is now a popular site for swimming, sunbathing, fishing, walking on a boardwalk, and birdwatching. Watch a video tour of the park to hear about how the area was restored or check out CTDEEP’s State Parks web site for directions and advisories.


Field Notes
  • Charles Island is closed to the public from May 1 to August 31 to protect nesting heron and egret colonies.
  • Attempting to cross the connecting bar to Charles Island can be dangerous. Visitors should consult local tide predictions. Uninformed visitors have been trapped on the island and swept off of the bar at high water!
  • Dense stands of poison ivy are found throughout the island.

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