Bituminous coal and lignite seams of the United States and Alaska range from less than 2 feet in thickness to more than 50 feet, but the majority of the Nation's coal mines produce from seams 3 to 6 feet thick and the average of the country is 65 inches. Contains information on coal seams of the United States as well as other data on coal production from strip and underground bituminous coal and lignite mines 1945.