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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

Frequently Asked Questions

Latest News

Power lines. Image Credit: U.S. Department of Energy
January 23, 2018 The Senate Energy and Natural Resources Committee held a hearing on January 23 that underscored concerns surrounding the reliability and resiliency of the electrical power system, particularly under certain weather conditions, such as the deep freeze or bomb cyclone that the U.S....
Nuclear power plant, Czech Republic
January 8, 2018 On January 8, the Federal Energy Regulation Commission (FERC) rejected a proposal that was submitted by Secretary of Energy Rick Perry in September 2017 to subsidize the operating costs of coal and nuclear power plants, since the rule did not satisfy certain statutory standards....
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. Department of the Interior

The U.S. Department of the Interior's Office of Natural Resources Revenue, Information and Data Management 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...

Screenshot of the USEITI case studies showing the Boone, Logan and Mingo counties case study highlighted
U.S. Department of the Interior

The U.S. Department of the Interior's Office of Natural Resources Revenue, Information and Data Management 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...

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 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 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 PUB111; Source: Virginia Department of Mines, Minerals and Energy
1991, Virginia Division of Geology and Mineral Resources (VA DGMR)
This study indicates that at the time of publication the coal resources in Lee County 944-millions short tons of coal originally existed, of which 72-million short tons have been mined, leaving 871-million short tons of remaining coal.
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 GF15; Source: Ohio Geological Survey
2014, Ohio Geological Survey (OGS)
Coal has been mined in Ohio since 1800. Mining technology has evolved from pick and shovel to the highly automated, computer-controlled equipment used today. There are two basic types of coal mines: surface mines and underground mines. Since 1800, approximately 3.9 billion tons of coal have been...
Coal Geology of Iowa - 2002 Keystone Coal Industry Manual, Iowa Geological Survey
2002, Iowa Geological Survey (IGS)
Most of Iowa's coal production has been from coals in the Cherokee Group. Lesser production has come from the Marmaton Group, and other minor production from the Virgil Supergroup. Most coal produced in th e state supplies electric utilities and industry.
Cover of c-118; Source: Utah Geological Survey
2014, Utah Geological Survey (UGS)
During 2013, Utah extractive resource industries produced energy and mineral commodities with an estimated gross value of $9.5 billion. On an inflation-adjusted basis, this is a $1 billion (12%) increase from 2012, and $1.2 billion (11%) less than the 2008 record high of $10.7 billion. Total energy...
1975 Summary of Coal Resources in Colorado, Colorado Geological Survey
1976, Colorado Geological Survey (CGS)
Within the borders of Colorado, and covering approximately 28 percent of the State, occur 8 coal-bearing regions and some 20 coal fields that contain at least 11 percent of the total coal resources of the United States above 6,000 feet. Over 70 percent of the State's coal resources are bituminous...
Cover of ofr2013-01; Source: Wyoming State Geological Survey
2013, Wyoming State Geological Survey (WSGS)
Presented in this report are the results of a regional groundwater drawdown study that is being conducted by the BLM within its monitoring well network. This report will add and focus on data from January 2010 through October 2012 (hereafter referred to as the period of record or POR). Additionally...
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-...