This publication is the fifth in a searies of reports by the U.S. Geological Survey on the assessment of the quantity and quality of the nation's coal deposits that potentially can be mined during the next few decades. For eight years (1995-2003), geologic, geochemical, and resource information was collected and compiled for the five major coal-producing regions of the United States. This volume contains the assessment results for the Gulf of Mexico Coastal Plain region. The contents of this volume were compiled mainly during the 8-year period mentioned above. However, every effort has been made to update the references and text to incorporate new work that has been completed since the original compilation period.