Summary
According to the Palisades Parks Conservancy website: "Haverstraw Beach State Park is a component of the larger Rockland Lake State Park complex. The park is just north of the Rockland Lake golf course, on the east side of Route 9W.
In 1780, American General Benedict Arnold and the British spy John André exchanged the plans to West Point at Haverstraw Beach. A stone marker identifies the placewhere Andre landed. This site, the location of an early town named Snedeker's Landing, is also known as the oldest shipyard in Rockland County. It built barges to ferry brick from the nearby brickyards in Haverstraw to New York."