www.LIHomeAuction.com ,  www.LIWaterfrontProperties.com , &  www.PrudentialElliman.com ,  www.prudential.com/realestate .   Cold Spring Harbor Information Cold Spring Harbor is a hamlet (and census-designated place ) in Suffolk County , New York on the North Shore of Long Island . As of the United States 2000 Census , the CDP population was 4,975. Cold