The early history of Silver Sands focuses on Charles Island. The Island is connected to the mainland by a sand/gravel bar (tombolo) that is submerged at high tide. Captain Kidd is reputed to have buried his treasure on the island in 1699. The only remains on the island are of a Catholic retreat center from the 1920's-30's. The island's interior is closed May 1 through August 31 to protect heron and egret rookeries.
State Park acquisition, ultimately involving over 300 parcels, began after hurricane "Diane" destroyed 75 homes in 1955. Early vision of the park was to create a "Hammonasset" type sand beach backed by parking lots on filled wetlands. The present master plan seeks to return the site to its historic past of interior tidal wetlands separated from the Sound by sand dunes. In 1960 Silver Sands was designated as a state park.