- =  No data are reported.
  W = Data withheld to avoid disclosure.
  NA = Not Available.
Notes:  · Recoverable coal reserves at producing mines represent the quantity of coal that can be recovered (i.e. mined) from existing coal reserves at reporting mines. · EIA's estimated recoverable reserves include the coal in the demonstrated reserve base considered recoverable after excluding coal estimated to be unavailable due to land use restrictions or currently economically unattractive for mining, and after applying assumed mining recovery rates; see Glossary for criteria.  · The effective date for the demonstrated reserve base, as customarily worded, is "Remaining as of January 1, 2007."  These data are contemporaneous with the Recoverable Reserves at Producing Mines, customarily presented as of the end of the past year's mining, that is in this case, December 31, 2006. · The demonstrated reserve base includes publicly available data on coal mapped to measured and indicated degrees of accuracy and found at depths and in coalbed thicknesses considered technologically minable at the time of determinations; see Glossary for criteria.  · All reserve expressions excludes silt, culm, refuse bank, slurry dam, and dredge operations. · Reserves at Producing Mines excludes mines producing less than 10,000 short tons, which are not required to provide reserves data.
Source:  · Energy Information Administration Form EIA-7A, "Coal Production Report," and U.S. Department of Labor, Mine Safety and Health Administration, Form 7000-2, "Quarterly Mine Employment and Coal Production Report," and EIA estimates.