R. M. Flores J. Hatch M.A. Kirschbaum L.F. Ruppert Peter D. Warwick Harold J. Gluskoter 1996 <p>In 1994, coal production in the United States reached the highest level in history (slightly more than 909 million metric tons or one billion short tons), continuing the upward trend of coal production and utilization that began 34 years ago. Previous assessments of the coal resources of the United States, which were completed as early as 1909, clearly indicated that the total coal resources of the Nation are large and that utilization at the current rate will not soon deplete them.</p> application/pdf 10.3133/fs15796 en U.S. Geological Survey Assessing the coal resources of the United States reports