from the park
Marshall Field III bought the property in 1921 and had an estate house built in 1925, one of the largest estates of the
Gold Coast mansions. Field named the property "Caumsett", after the
Matinecock tribe's original name for the peninsula meaning "place by a sharp rock". The Marshall Field III estate was purchased by New York State for $4 million on February 3, 1961, and became a state park. The former estate was listed on the
National Register of Historic Places in 1979. Although right-of-way was acquired, the parkway was never built. A portion of this land was later used to create
Cold Spring Harbor State Park and
Trail View State Park. In January 2026, 180 acres of the former Seminary of the Immaculate Conception, located directly south of the existing park, were acquired by the New York State Office of Parks, Recreation and Historic Preservation. This addition encompasses 12 acres of estuarine and marine wetlands as well as bluffs and steep slopes adjacent to Lloyd Neck Harbor. ==Park description==