In the past two years, more than half of U.S. coal production was attributable to the top four coal producers, the result of changes in regional production as well as decades-long trends towards the concentration of coal production around the top few companies. Peabody Energy Corporation, Arch Coal Inc., Alpha Natural Resources LLC, and Cloud Peak Energy together supplied 575 million tons, or 52% of total U.S. coal production, in 2011, while more than 500 other companies supplied the remaining 48%. By comparison, the fifth largest coal producer in 2012, Consol Energy Company, contributed 34 million tons, or 35% less than fourth-place Cloud Peak Energy.

via Top four U.S. coal companies supplied more than half of U.S. coal production in 2011 – Today in Energy – U.S. Energy Information Administration (EIA).