Coal fields of the conterminous United States—National Coal Resource Assessment updated version

This map sheet with accompanying Geographic Information System (GIS) project is an update of the existing U.S. Geological Survey (USGS) Conterminous U.S. Coal Fields map. This update was compiled using data primarily from the USGS National Coal Resource Assessment (NCRA) and information from other published maps. The five regions examined by NCRA (Eastern, Gulf Coast, Interior, Rocky Mountain, and Northern Great Plains) constituted 93 percent of U.S. coal production at the time of the assessments. The map sheet shows aerial extent, rank, province, name (region and field), and age information, which are also attributes of the GIS project. Due to changing technological and economic constraints for coal usage, along with the potential for geologic carbon dioxide sequestration, this map sheet and the GIS component of this report do not differentiate between potentially minable coal and uneconomic coal. Additional figures on the map sheet show coal formations, current production by State, coal rank definitions, and charts showing historical trends of coal production.