Pen-and-ink on 3 separate sheets, taped together along the edge, and mounted between sheets of transparent paper. Pencil (some col.), mounted between sheets of transparent paper. LC Civil War maps (2nd ed.), H322 Includes a geological cross section: Geological section across Upper Potomac Coalfield. In ink and pencil: 982(a), 982(b), 982(c). Available also through the Library of Congress web site as raster image.