Ellisville Harbor State Park on the western shore of Cape Cod Bay in Massachusetts is a coastal preserve that pairs public access with protection of barrier beach, salt marsh, sphagnum bog, meadows, and red pine forest. The site also preserves a long human story: prehistoric Native Americans used the area between about 2,500 and 5,000 years ago, and the harbor later served timber shipments to Boston and local fishing. About 600 acres were designated an Area of Critical Environmental Concern in 1980, and the state acquired 100 acres in 1991 to create the park. Today it is valued for wildlife habitat, scenic views, and low-impact recreation.