Coal is a carbon-rich rock formed from plants that grew millions of years ago. Coal is a major source of electricity in the United States and the largest source of energy for electricity generation worldwide.


A coal-fired power plant in Westport, Kentucky on the Ohio River. Image Copyright © Michael Collier.

Coal is a rich source of energy formed from plants that grew in swamps tens to hundreds of millions of years ago. The plants were buried deeply under younger and younger layers of dirt and rock, heated, and compressed into a carbon-rich rock.[1] Burning coal releases more carbon dioxide per unit of energy produced than any other fossil fuel.[2]   Read more

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Latest News

Excavator mining
May 25, 2017 The House Natural Resources Subcommittee on Energy and Mineral Resources held a legislative hearing on a discussion draft of the Community Reclamation Partnerships Act (H.R.__) to be introduced by Representative Darin LaHood (R-IL-18). This legislation would streamline efforts to clean...
Nuclear power plant, Czech Republic
February 16, 2017 Rep. Keith Rothfus (R-PA-12) introduced legislation (H.R.1119) to modify existing regulations applying to coal-refuse-to-energy power plants on February 16. The bill acts to exempt these specific power plants from emission standards required under the Environmental Protection...
#MapOfTheDay! Check out this interactive map of Iowa coal mines from @iowadnr
#MapOfTheDay! Today the Critical Issues Program (@AGI_GeoIssues) shared an interactive map of coal mines in Iowa from the Iowa Department of Natural Resources (@IowaDNR), which you can find at For information about coal mining, check out our Coal Basics.
Excavator mining
August 9, 2016 The Department of the Interior’s (DOI) Office of Surface Mining Reclamation and Enforcement (OSMRE) has issued guidance suggesting that states move away from accepting self-bonding, where companies use their current financial health as collateral to guarantee reclamation of lands...
June 22, 2016 The White House Council of Economic Advisers (CEA) released a report entitled, “The Economics of Coal Leasing on Federal Lands: Ensuring a Fair Return to Taxpayers”. This report is part of a larger ongoing review of the federal coal leasing program – the first such review since the...
April 5, 2016 The Environmental and Energy Study Institute (EESI) held a webinar entitled, “Can Coal Country Thrive in a Clean Energy Economy?” The speakers were Tara Ritter of the Institute for Agriculture & Trade Policy, Julie Lawhorn of the Appalachian Regional Commission (ARC), Brett...
March 25, 2016 The Department of the Interior (DOI) released a notice of intent (NOI) that the Bureau of Land Management (BLM) will prepare a Programmatic Environmental Impact Statement (PEIS) to evaluate potential reforms to the federal coal program. The NOI comes after a DOI announcement in...

Case Studies & Factsheets

Screenshot of the USEITI case studies showing the Campbell County case study highlighted
U.S. Extractive Industries Transparency Initiative

The U.S. Extractive Industries Transparency Initiative (USEITI) has produced a series of case studies on extractive industries across the United States, focusing on coal, copper, gold, iron, natural gas, and oil. The case study on coal mining in Campbell County, Wyoming can be found here. The...

Screenshot of the USEITI case studies showing the Boone, Logan and Mingo counties case study highlighted
U.S. Extractive Industries Transparency Initiative

The U.S. Extractive Industries Transparency Initiative (USEITI) has produced a series of case studies on extractive industries across the United States, focusing on coal, copper, gold, iron, natural gas, and oil. The case study on coal mining in West Virginia's Boone, Logan, and Mingo counties...

Fig. 1. Exposure of sandstone capping an economic coal bed. Credit: J. Shaulis, Pennsylvania Geological Survey

Defining the Problem Despite Pennsylvania’s long history as a major coal producer, information on the coal geology (Fig. 1), remaining resources, and extent of past mining is not available for many areas of the state. Such information is critical for present and future coal exploration and...

Research Database Publications

Cover of GF16; Source: Ohio Geological Survey
2015, Ohio Geological Survey (OGS)
Coal is a black or dark brown, combustible sedimentary rock. It contains greater than 70% carbon-rich material by volume. Since the 1880s, coal has been burned to produce electricity, and today, the electric utility industry is the largest consumer of coal in the nation. The coal used in Ohio for...
Cover of OFR04-37 ; Source: Kansas Geological Survey
2004, Kansas Geological Survey (KGS)
Exploration for and the production of natural gas from coal (termed coalbed methane or CBM in the report) continues to develop rapidly in eastern Kansas and especially in southeast Kansas. During this study period 1774 wells were determined to have been drilled for exploration or production of...
Cover of MBMG 651 ; Source: Montana Bureau of Mines and Geology (MBMG)
2014, Montana Bureau of Mines and Geology (MBMG)
This report presents groundwater data collected through September 2013 from within the Montana portion of the Powder River Basin, with an emphasis on data collected during water year 2013 (October through September). This is the 11th year in which the Montana coalbed-methane (CBM) regional...
Cover of OFR04-09 ; Source: Kansas Geological Survey
2004, Kansas Geological Survey (KGS)
Coal is the most abundant energy source in the world, and it is a major source of hydrocarbons, particularly gas. The coalification process, whereby plant material is progressively converted to coal, generates large quantities of methane-rich gas, which are stored within the coal. The presence of...
Cover of OFR 2016-2; Source: Ohio Geological Survey
2016, Ohio Geological Survey (OGS)
The Ohio Department of Natural Resources (ODNR), Division of Geological Survey (Ohio Geological Survey) performed an estimation of the remaining and available resources of the Pittsburgh (No. 8) coal bed in Ohio. This study represents the first statewide estimation of Pittsburgh coal resources in...
Cover of ofr20161033; Image credit: U.S. Geological Survey
2016, U.S. Geological Survey (USGS)
In 2011, the U.S. Environmental Protection Agency (EPA) introduced emissions standards, known as Mercury and Air Toxics Standards (MATS), for a range of toxic constituents from coal-fired utility power stations and other combustion sources. This report presents the findings of an expert panel...
Cover of SP98-6 ; Source: Oklahoma Geological Survey
1998, Oklahoma Geological Survey (OGS)
Mcintosh County is located in the east-central part of the coal belt of eastern Oklahoma, and almost the entire county is underlain by coal-bearing strata of Desmomesian (Middle Pennsylvanian) age. For lack of data about coal depth and thlckness, resource potential is unknown for ~75% of the county...
Cover image of position statement; Image credit: SME
2012, Society for Mining, Metallurgy, and Exploration Inc. (SME)
In a future world of 8.5 billion people in 2035, the Energy Information Administration’s (EIA) projected 50% increase in energy consumption will require true “all of the above” energy resource use from oil, gas, renewables, nuclear, and coal. In particular, coal will continue to be the world’s...
Cover of PP1625f; Source: USGS
2009, U.S. Geological Survey (USGS)
The U.S. Geological Survey (USGS) has completed the National Coal Resource Assessment (NCRA), a multiyear project by the USGS Energy Resources Program, in partnership with State geological surveys in the coal producing regions of the United States. The NCRA is the first digital national coal-...
Cover of PP1625d; Source: USGS
2002, U.S. Geological Survey (USGS)
The goal of this resource assessment of Illinois Basin coals is to provide an overview of the geologic setting, distribution, resources, and quality of Pennsylvanian-age coals in the basin as part of the U.S. Geological Survey's National Coal Resource Assessment Project (NCRA). The area of coal-...