The Ohio-based Institute for Energy Economics and Financial Analysis, a group with environmental ties, has pegged lost revenues at more than $30 billion since the early 1980s, when many of the rules governing the industry were last revised.
The Powder River Basin of Wyoming and Montana accounts for the overwhelming majority of the public coal sales, 90 percent of which involve four industry giants — Arch Coal, Peabody Energy, Alpha Natural Resources and Cloud Peak Energy.
Most of the fuel is burned in U.S. power plants. But as domestic sales have lagged amid competition from cheap natural gas, more U.S. coal has been shipped abroad.
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