DescriptionUnited States Department of Interior Geological Survey, U.S. Department of the Army Corps of Engineers, Chester Quadrangle, 7.5 Minute Series, Topographic – in color, 1954, photorevised in 1970. The topography was determined by aerial photography by photogrammetric methods. Original photographs taken in 1942. Updates have been periodic. The map is tinted to show different zones, updates, and areas of urban expansion.