The Indiana Coal Field occupies 6,500 square miles of southwestern covering almost 25 counties. The terrain varies from flat to hilly with small, steep-sided slopes. It is along the eastern edge of the spoon shaped Illinois Basin. This is a structural depression that covers parts of three states: Indiana, Kentucky , and Illinois. The coal seam dips about 25 feet per mile to the west, reaching to the middle of the Illinois Basin.
For a look at the Indiana coal region and specific mine visit the Division of Reclamation's Web page.