The U.S. coal industry has undergone a remarkable transformation over the last three decades. During this time, coal production has doubled, while the number of active miners has been halved and the number of mines has dropped by a factor of three (Figure 4.1). This has resulted in the concentration of production in a smaller number of larger mines. The 100 largest mines in the country produced 805 million tons of coal in 2004 (72.5 percent of total U.S. production), while employing about 45 percent of the mining workforce (an average of 310 miners per mine) (EIA, 2005d; NMA, 2006a). The remaining approximately 1,300 mines produced 27.5 percent of the nation’s coal while employing 55 percent of the workforce (about 30 miners per mine). Nearly 70 percent of U.S. coal mines, many of which are comparatively small operations, are in Kentucky, West Virginia, and Pennsylvania.
Since the 1970s, there has been a continuous increase in the proportion of coal produced by the western states. At present, states west of the Mississippi account for more than 55 percent of total tons produced (Figure 4.2). Wyoming alone accounts for almost 36 percent of national coal production tonnage (Table 4.1).
Considerable data are compiled on the basis of the union or non-union status of mines throughout the coal industry by the Energy Information Administration (EIA). At present, some 27.5 percent of the total coal mining workforce consists