Mallard Island

Mallard Island is a small island in Suisun Bay, at the confluence of the Sacramento and San Joaquin rivers. It is part of Contra Costa County, California. Its coordinates are 38.04194°N, -121.91861°W, and the United States Geological Survey measured its elevation as 3 ft in 1981. It appears in a 1953 USGS map of the area.