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Coal What is Coal Coal Resources & Reserves Coal Production & Mining Coal Geology Coal Mining History Coal Maps & Projects Powder River Basin

Coal Diagrams, Data, Maps & Projects

Coal is found in many parts of Wyoming at outcrops and in the subsurface. Coal production takes place where economic, geologic, political, and environmental factors allow for mining operations. Most of the coal produced in Wyoming is transported out of state for consumers. This page contains links to maps, Google Earth files, GIS datasets, and WSGS publications describing the locations of coal resources and mining activity in Wyoming.

Summary Report

Wyomings Coal Resources
Download the 2015 Wyoming's Coal Resources Summary Report.


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Coal Map of Wyoming
Download the 2011 WSGS Coal Map of Wyoming.

WY Coal MinesWyoming Active Coal Mining Map
View Wyoming coal mines, power plants, and coal resources in Google Earth.

View or Purchase
The Coal Map of Wyoming and other WSGS coal publications can be viewed or purchased online.

1951 USGS Map 1951 USGS Coal Fields Map
Download the USGS 1951 Coal Fields Map of Wyoming.


GIS iconGIS Data
Downloadable GIS coal and coalbed methane datasets available from WSGS.

Excel iconDemonstrated Reserve Base
Download an Excel file containing state rankings and the demonstrated coal reserve base estimated in 1973.

Excel iconWY NCRDS Stratigraphic Data
Download an Excel file containing the Wyoming NCRDS stratigraphic data entered since 2013.

Excel iconActive and Historic Coal Mines and Samples
Download an Excel file containing data of active and historic coal mines and samples, updated 2017.

Coal Mining Diagrams

Surface Mine Surface mining
Surface mining
Download a diagram showing surface mining methods used by coal mines today. Illustration by James Rodgers.

Underground Mine Underground mining
Underground mining
Download a diagram showing underground coal mining showing a long wall operation. Illustration by James Rodgers.

Greater Green River Basin Project

GGRB study area.

The Wyoming State Geological Survey (WSGS) recently researched coal in the eastern part of the Greater Green River Basin through outcrop and subsurface studies of the Paleocene Fort Union Formation. This work involved field mapping funded through the USGS Statemap program, analysis of existing oil and gas well logs from the Wyoming Oil and Gas Conservation Commission, examination of cores from the USGS core repository, and subsurface information from the National Coal Resource Data System (NCRDS). These data were used to correlate subsurface coal within the Fort Union Formation to known coal outcrops along the margins of the basin, and to provide an estimate of coal available for mining.

The Greater Green River Basin is a foreland basin that formed during the Laramide orogeny, approximately 65 million – 55 million years ago, and is subdivided by minor Laramide structures into smaller basins such as the Washakie and Great Divide Basins, which were the focus of this study. Approximately 60 million years ago, Wyoming was covered by vast swamps that were lithified into numerous thick coal seams, generating coal resources that are among the largest in the world. The Great Divide and Washakie Basins were selected for study because active coal mining is occurring along the western margins of these basins; the Fort Union Formation was examined because its coals are mined at both the Bridger and Black Butte Coal Mines at a rate of more than 6 million short tons per year.

For the subsurface portion of this study, Fort Union coals were correlated in 3,018 wells, more than 83 individual coal beds were identified, and the 12 thickest and most laterally continuous mineable coal beds were modeled to determine available coal resources. More than 82 billion tons of coal were determined to be recoverable from the modeled Fort Union coal beds. Although the majority of Fort Union coals are too deep to mine in the basin centers, there are abundant coals of underground mineable depths on both the east and west margins of the basins. The stratigraphic data set is available under the Maps & Data tab on this page.

The WSGS is currently correlating Fort Union coals of the western side of the Greater Green River Basin as part of the NCRDS program for 2017. Those results should be available in 2018-2019.

NCRDS Coal Stratigraphic Database

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The Wyoming State Geological Survey (WSGS) participates in a cooperative program with the U.S. Geological Survey’s (USGS) Energy Resources Program. This program includes the National Coal Resource Data System (NCRDS), which represents a joint project between the USGS and state geological surveys for the coal-bearing states. This national project involves collecting stratigraphic coal resource information from coal exploration holes, coalbed methane wells, and coal measured sections.

For more than 30 years, the WSGS has collected coal stratigraphic and coal quality data from Wyoming’s 10 coal fields (as defined by Lane and others, 1972; see map on coal homepage). Much of these data come from historical coal mine information, geologic publications, and public contributions from coal companies with active mining operations throughout Wyoming. Detailed information includes location, coal bed thickness, elevation, depth, stratigraphic position, and interbedded lithologies.

Subbituminous coal outcrop, Fort Union Formation, Southwest Wyoming The WSGS has developed the Wyoming NCRDS Coal Stratigraphic Database to provide information on the location and stratigraphic intervals from 30,814 public points (wells or measured sections). Most of the points are located in the Powder River Basin from more than 14,000 coalbed methane wells. The use and access of these data are important for regional coal resource evaluations of Wyoming’s basins. Energy industry scientists, state and federal government regulators, and the general public use the NCRDS data.

A link to the Wyoming NCRDS stratigraphic data is provided under the Maps & Data tab on this page. Since 2013, the WSGS has added 6,219 points to the stratigraphic collection from work in the Powder River, Great Divide, Washakie, and Green River basins. More information about the NCRDS stratigraphic databases can be found at the U.S. Geological Survey website.

Reference: Lane, D.W., Root, F.K., and Glass, G.B., 1972, Energy resources map of Wyoming: Geological Survey of Wyoming [Wyoming State Geological Survey] Map Series 2, scale 1:500,000.

Click here for additional resources list

Consensus Revenue Estimating Group

Wyoming Department of Environmental Quality

Wyoming Mining Association

Wyoming Mines Inspection and Safety

U.S. Energy Information Administration

U.S. Geological Survey

Office of Surface Mining Reclamation and Enforcement

Mineral Information Institute

U.S. Bureau of Land Management

University of Wyoming, School of Energy Resources