Deer Creek Marsh Wildlife Management Area is an 1,195-acre (484 ha) New York State Wildlife Management Area (WMA) with a 4,500-foot (1,400 m) sandy beach on the eastern shore of Lake Ontario; it is in the Town of Richland in Oswego County, New York. Deer Creek Marsh lies at the southern limit of a 17-mile long region of sandy barrier beaches that protect coastal lagoons and marshes; the region is unusual geologically and is important as habitat for many species. Deer Creek Marsh WMA is part of the Eastern Lake Ontario Marshes Bird Conservation Area, along with Black Pond and Lakeview WMAs and the Sandy Pond Beach Unique Area.