Notes:

This dataset is a polygon shapefile representing the most recentupdate of the coal fields of the conterminous United States. Scale ofdata is 15,000,000. This publication is based on a USGS paper mapthat was a representation of the coal fields and major regions of thetime (Trumbull, 1960). Trumbull's 1960 map was digitized and coalfields from the Gulf Coast were added to create USGS OFR 96-92, CoalFields of the Conterminous United States (Tully, 1996). Tully's(1996) publication consisted of a map in pdf format that could beprinted, and an ArcInfo coverage of the coal fields, attributed withrank and potential economic use (minability) of the coal. This newdataset includes a pdf showing updated coal fields and a shapefilethat contains attributes on coal rank (without regard to outdatedeconomic standards), province, name, and age. The data used to updateTully's (1996) digital map was collected from the National CoalResource Assessment (NCRA) regional Professional Papers produced bythe USGS and from AAPG Discovery Series 14/Studies in Geology 62, allof which were conducted by USGS geologists and professional staff. Asmall number of field names were added and or updated in the westernstates of Washington, Oregon, California, Utah, Colorado and NewMexico using additional coal resource literature.The full study is available from USGS https://doi.org/10.3133/ofr20121205