Coal mining operations at the ColoWyo Coal Mine, Moffat and Rio Blanco Counties. Photo credit: Mike O'Keeffe (CGS)

Coal

Intro

Coal extraction has a long and complex history in Colorado. It has been mined commercially in the state since 1864 when it was used for local residential heating. Smaller amounts of coal were mined as far back as 1859 when a local landowner excavated coal from his property and sold it to homesteaders for heating fuel. Coal production expanded in the 1860s-70s, as a result of the demands associated with the Colorado Gold Rush. Later, around the turn of the 20th Century, it was employed for brick and steel production. Most coal currently mined in Colorado is for power generation.

The estimated value of Colorado coal production in 2015 was $675 million, decreasing to $602 million in 2019. In 2020, the estimated value of statewide coal production was $441 million, giving Colorado the rank of thirteenth largest among coal producing states. The overall decreasing trend in coal production is due primarily to the increased nationwide use of natural gas and renewable energy. Coal from the state is mostly bituminous and sub-bituminous—with both underground and surface mines currently in operation on the Western Slope—and is characterized by its high heat, low sulfur, low to medium ash, and low mercury content.

Details

More detailed reviews of Colorado coal regions, resources, and geology are presented in two CGS publications including a 2005 Rocktalk and a 2003 summary of coal resources in the state. Coal-bearing geological formations underlie ~28% of the state and range in age from the Lower Cretaceous to the Eocene. As of 2022, coal is mined in Gunnison, La Plata, Moffat, Rio Blanco, and Routt counties at six mines.

Most coal produced in Colorado is used for power generation but continues to decline primarily due to low natural gas prices, federal greenhouse gas regulations and taxes designed to cut carbon dioxide emissions, along with the declining cost and growing use of renewable energy sources. In 2010, Colorado passed the Clean Air, Clean Jobs Act which promotes the replacement of Front Range coal-fired power plants with natural gas plants. Since 2010, several Colorado coal-fired plants and units have been shut down or converted to natural gas. Several more coal-fired plants will either shut down or convert to natural gas in the near future. About 36% of the electricity generated in Colorado in 2020 came from coal-fired power plants. For comparison, in 2015, 60% of the electricity generated in Colorado came from coal indicating a rapid move away from energy production from coal.

Colorado coal production continues to decline from a high of ~39.8 million tons in 2004 to ~10.6 million tons in 2020. In response, coal mining employment in Colorado dropped from a high of ~2,279 in 2012 to ~901 people in 2020. The Colorado Division of Reclamation, Mining and Safety is responsible for implementing and enforcing the Colorado coal mining regulatory program including mine permitting, bonding, and inspection.

Coal is an organic clastic sedimentary rock composed mostly of ancient plant material. It is combustible because it contains carbonized, solid but brittle, ancient plant matter. Originally deposited as leaf-litter and plant remains in a fresh-water environment, the material first begins as peat, as in a peat bog. Over time it is compressed, dried, and modified by heat and pressure by sedimentary layers that cover it and by the proximity to the heat of the earth. This process is called ‘coalification’. The peat then undergoes diagenesis with depth of burial and tectonic forces. Coal, a black-to-brown rock, is the end product of this diagenetic process. The more complete the process, the higher the grade, or rank of the coal.

Excavator working Wadge coal seam, a year before the Yoast Mine, 25 miles west of Steamboat Springs, closed in 2006. Photo credit: Chris Carroll for the CGS.
Excavator working Wadge coal seam, a year before the Yoast Mine, 25 miles west of Steamboat Springs, closed in 2006. Photo credit: Chris Carroll for the CGS.

Texturally, coal is subdivided into four main classes: lignite, sub-bituminous, bituminous, and anthracite. This last class is the hardest coal and contains the most carbon. Lignite is the least dense coal with lower carbon content. Coal, a sedimentary rock, is composed mostly of carbon, hydrogen, oxygen, nitrogen (volatile hydrocarbons), and lesser amounts of ash, sulfur, and trace elements.

Bituminous and sub-bituminous coals make up the majority of Colorado’s coal resources, and are mined as clean low-sulfur but high-heat content coal products. Generally, the higher rank bituminous coals are found in the Cretaceous age Dakota and Mesaverde groups in western Colorado from Moffat County south to the state line. Anthracite occurs in Gunnison and Pitkin counties, and lignite is found in the Paleocene-age Denver Formation in the Denver Coal Region.

The North Fork of the Gunnison River flows past the stockpile and loadout facilities for Arch Coal's West Elk Mine in Gunnison County, Colorado. June 2004. Photo credit: Chris Carroll for the CGS.
The North Fork of the Gunnison River flows past the stockpile and loadout facilities for Arch Coal’s West Elk Mine in Gunnison County, Colorado. June 2004. Photo credit: Chris Carroll for the CGS.

Coal in Colorado was formed in peat mires during the Cretaceous and Paleocene-Epoch of the Tertiary Period, between ~100 and 55 million years ago. Fresh-water bogs formed along the coastal plains adjacent to the shorelines of the Western Interior Seaway that existed in the mid-continent during this time. The climate was hot, the sea level was generally high, and the seaway shorelines fluctuated greatly through geologic time. Lignite deposits in the Denver Formation were deposited after the Western Interior Seaway receded and likely formed in fresh water swamps on the east side of the piedmont extending from the Front Range (Kirkham and Ladwig, 1979).

Coal forms during four critical stages as summarized below.

Stage 1 is the accumulation stage, where peat, or parent material of coal, accumulates in freshwater marshes, swamps, and rainforests. The accumulation of organic material must exceed the oxidation or biodegradation of the environment.

Stage 2 is called the burial and preservation stage. Conditions of subsidence and fresh-water preservation and burial must be critical for coal to form.

Stage 3 is the diagenesis and coalification stage where peat is transformed or metamorphosed to form coal. Heat and pressure geochemically alter the organic material into coal. Regional heat flow, such as in parts of Colorado, also alter the process in sedimentary basins to where the coal rank is upgraded, sometimes from bituminous coal to anthracite. This entire process is called “coalification. ”

During coalification, peat undergoes several changes as a result of bacterial decay, compaction, heat, and time. Peat deposits are quite varied and contain everything from pristine plant parts (roots, bark, spores, etc.) to decayed plants, decay products, and even charcoal if the peat caught fire during accumulation. Peat deposits typically form in a waterlogged environment where plant debris accumulated; peat bogs and peat swamps are examples. In such an environment, the accumulation of plant debris exceeds the rate of bacterial decay of the debris. The bacterial decay rate is reduced because the available oxygen in organic-rich water is completely used up by the decaying process. Anaerobic (without oxygen) decay is much slower.

For the peat to become coal, it must be buried by sediment. Burial compacts the peat and, consequently, much water is squeezed out during the first three stages of burial.

Stage 4 is the continued burial and the addition of heat and time causing the complex hydrocarbon compounds in the peat to break down and alter in a variety of ways. The gaseous alteration products (methane is one) are typically expelled from the deposit, and the deposit becomes more and more carbon-rich as the other elements disperse. The stages of this trend proceed from plant debris through peat, lignite, sub-bituminous coal, bituminous coal, anthracite coal, to graphite (a pure carbon mineral).

Because of the amount of squeezing and water loss that accompanies the compaction of peat after burial, it is estimated that it took 10 to 15 vertical feet (3 – 5 m) of original peat material to produce one vertical foot (0.3 m) of bituminous coal in Colorado. The peat to coal ratio is variable and dependent on the original type of peat, coal rank, length of time of burial, and the depth at which it was buried.

Metallurgical Coal

Coal is used to make coke for the iron and steel industry, foundries, and other industries. The presence of large domestic deposits of coking coal, or metallurgical coal, played an important role in the development of the U.S. iron and steel industry. Coke is used chiefly to smelt iron ore and other iron bearing materials in blast furnaces, acting both as a source of heat and as a chemical reducing agent, to produce pig iron, or hot metal. Coke, iron ore, and limestone are fed into the blast furnace, which runs continuously. Hot air blown into the furnace burns the coke, which serves as a source of heat and as an oxygen reducing agent to produce metallic iron. Limestone acts as a flux and also combines with impurities to form slag.

Foundries use coke as a source of heat for producing metal castings. Other industrial uses of coke include the smelting of phosphate rock to produce elemental phosphorus and the production of calcium carbide. Small sizes of coke, termed breeze, are used as fuel in sintering finely sized particles of iron ore and other iron bearing material to produce an agglomerate that can be used in a blast furnace.

Coke is made by baking a blend of selected bituminous coals (called metallurgical coal or coking coal) in special high temperature ovens without contact with air until almost all of the volatile matter is driven off. The resulting product, coke, consists principally of carbon. A short ton of coal yields about 1,400 pounds of coke and a variety of byproducts such as crude coal tar, light oils, and ammonia, which are refined to obtain various chemical products. About 1,100 pounds of coke are consumed for every short ton of pig iron produced.

Colorado Coal Regions

Coal mining was first reported in 1859 and the first recorded official coal production was in 1864. Coal was first mined from horizontal seams south of Boulder in the Marshall area, and in vertical seams in Golden. There are eight major coal regions in Colorado. Historically, coal has been mined from all of these coal regions. There have been over 1,700 coal mine operations in Colorado’s history. On the Western Slope are the Green River, Uinta, San Juan River coal regions. On the eastern slope are the Denver, Raton, and Canon City coal regions. In the central part of Colorado are the North Park and South Park coal regions. Most of the coal mined today comes from northwest Colorado in the Uinta and Green River coal regions.

Mine and tipple, Huerfano Coal Company, Ludlow Mine, Ludlow, Colorado, June 1946. Photo credit: Russell Lee.
Mine and tipple, Huerfano Coal Company, Ludlow Mine, Ludlow, Colorado, June 1946. Photo credit: Russell Lee.

Coal is a less glamorous commodity than gold and silver, but its economic importance was similar in 2020 with Colorado coal production valued at ~$441 million and gold production valued at $481 million. In addition to coal being mined from Golden to Boulder in the 19th century, Colorado Springs and Trinidad also saw extensive coal mining during that period. Some coal is shallow enough to the surface that it can be mined by open-pit methods, like those in Moffat County. In other places the layers extend beneath mountainous terrain, thus requiring deep underground mining, such as the mines in Gunnison and Delta counties.

Seneca II-W coal mine, Wolf Creek pit with excavators, Routt County, Colorado, October 2005. Photo credit: Chris Carroll for the CGS.
Seneca II-W coal mine, Wolf Creek pit with excavators, Routt County, Colorado, October 2005. Photo credit: Chris Carroll for the CGS.

Resources

Colorado Division of Reclamation, Mining and SafetyCoal mine production data and permitting.

U.S. Department of EnergyEnergy Information AdministrationCoalComprehensive information on national coal production and consumption.

U.S. Department of EnergyEnergy Information AdministrationColorado Energy OverviewComprehensive information on state-wide energy production and consumption.

U.S. Geological Survey – U.S. Coal Resources and Reserves AssessmentInformation about coal in Colorado and throughout the U.S.

U.S. Geological Survey – Coal fields of the conterminous United States—National Coal Resource Assessment (updated version) — Map-based information on coal fields with associated GIS data package.

U.S. Geological Survey – Map Showing the Extent of Mining, Locations of Mine Shafts, Adits, Air Shafts, and Bedrock Faults, and Thickness of Overburden Above Abandoned Coal Mines in the Boulder-Weld Coal Field, Boulder, Weld, and Adams Counties, ColoradoAn important compilation from 2001 made in collaboration with the CGS.

U.S. Office of Surface Mining Reclamation and Enforcement (OSMRE) — Regulates coal mines and abandoned mines on federal property.

Contents

Page Contents

Publications

Publications

Amuedo and Ivey. “EG-09 Coal Mine Subsidence and Land Use in the Boulder-Weld Coalfield: Boulder and Weld Counties, Colorado.” Coal Mine Subsidence. Environmental Geology. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1975. https://coloradogeologicalsurvey.org/publications/coal-mine-subsidence-land-use-boulder-weld-colorado.

 

Ayers, Jr., W. B., and W. R. Kaiser. “RS-31 Coalbed Methane in the Upper Cretaceous Fruitland Formation, San Juan Basin, New Mexico and Colorado.” Coalbed Methane. Resource Series. Denver, CO: Colorado Geological Survey, Division of Minerals and Geology, Department of Natural Resources, 1994. https://coloradogeologicalsurvey.org/publications/coalbed-methane-upper-cretaceous-fruitland-formation-san-juan-basin-new-mexico-colorado.

 

Barkmann, Peter. “WAT-2011-03 – Coalbed Methane Stream Depletion Assessment Study – Sand Wash Basin, Colorado.” Water Resources. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 2011. https://coloradogeologicalsurvey.org/publications/cbm-sand-wash-basin-colorado/.

 

Boreck, Donna L., D. C. Jones, D. Keith Murray, Janet E. Schultz, and Denise C. Suek. “IS-07 Colorado Coal Analyses, 1975.” Coal. Information Series. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1977. https://coloradogeologicalsurvey.org/publications/colorado-coal-analyses-1975.

 

Boreck, Donna L., and D. Keith Murray. “OF-79-01 Colorado Coal Reserves Depletion Data and Coal Mine Summaries.” Coal Resources. Open File Report. Denver. CO: Colorado Geological Survey, Department of Natural Resources, 1979. https://coloradogeologicalsurvey.org/publications/coal-reserve-depletion-data-coal-mine-summaries-colorado.

 

Boreck, Donna L., and Mark Strever. “OF-80-05 Conservation of Methane from Colorado’s Mined/Mineable Coal Beds: A Feasibility Study.” Coalbed Methane. Open File Report. Denver. CO: Colorado Geological Survey, Department of Natural Resources, 1980. https://coloradogeologicalsurvey.org/publications/mine-coal-beds-feasibility-study-conservation-methane-colorado.

 

Boreck, Donna L., Carol M. Tremain, Linda Sitowitz, and Thomas D. Lorenson. “OF-81-06 The Coal Bed Methane Potential of the Sand Wash Basin, Green River Coal Region, Colorado.” Coal Bed Methane. Open File Report. Denver. CO: Colorado Geological Survey, Department of Natural Resources, 1981. https://coloradogeologicalsurvey.org/publications/coal-bed-methane-potential-sand-wash-basin-green-river-colorado.

 

Brand, Karl E. “OF-80-01 Geophysical and Lithological Logs from the 1979 Coal Drilling and Coring Program, Denver East (1/2° x 1°) Quadrangle.” Coal Resources. Open File Report. Denver. CO: Colorado Geological Survey, Department of Natural Resources, 1980. https://coloradogeologicalsurvey.org/publications/geophysical-lithological-logs-1979-coal-denver-east-quadrangle-colorado.

 

Brand, Karl E., and Jennifer M. Caine. “OF-80-09 Geophysical and Lithological Logs from the 1980 Coal Drilling and Coring Program, Denver East (1/2° x 1°) Quadrangle.” Coal Resources. Open File Report. Denver. CO: Colorado Geological Survey, Department of Natural Resources, 1980. https://coloradogeologicalsurvey.org/publications/geophysical-lithological-logs-coal-drilling-coring-denver-east-quadrangle-colorado.

 

Brand, Karl E., and Wynn Eakins. “RS-13 Coal Resources of the Denver East (1/2° x 1°) Quadrangle, Colorado.” Coal Resources, 1:100,000. Resource Series. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1980. https://coloradogeologicalsurvey.org/publications/coal-resources-denver-east-quadrangle-colorado.

 

Broes, Lauren D., Asha Mahatma, M. Z. Che Zabri, Michael K. O’Keeffe, and John C. Hopkins. “ON-OF-78-08 Map and Well Logs from Drill Holes Used for Coal Evaluation in Denver and Cheyenne Basins, Colorado (See OF-78-08).” Well Log, Online. Golden, CO: Colorado Geological Survey, August 2020. https://coloradogeologicalsurvey.org/publications/map-well-logs-denver-cheyenne-basin-colorado.

 

Carlson, Jill, T. C. Wait, Brenda Hannu, Tom Hatton, and J. E. Turney. “IS-22 2010 Update: Annotated Bibliography of Subsidence Studies over Abandoned Coal Mines in Colorado.” Coal. Information Series. Denver, CO: Colorado Geological Survey, Department of Natural Resources, June 2010. https://coloradogeologicalsurvey.org/shop/bibliography-subsidence-studies-abandoned-coal-mines-colorado.

 

Carroll, C. J., and M. L. Morgan. “OF-00-12 Demonstrated Reserve Base for Coal in Colorado: Yampa Coal Field.” Coal. Open File Reports. Denver, CO: Colorado Geological Survey, Division of Minerals and Geology, Department of Natural Resources, 2000. https://coloradogeologicalsurvey.org/publications/demonstrated-reserve-base-coal-colorado-yampa-coal-field.

 

Carroll, Christopher J. “IS-71 Colorado Coal Directory, 2005, Includes Map of Coal Production and Distribution with Statistics on Electric Generation and Fuel Consumption.” Coal Resources. Information Series. Denver, CO: Colorado Geological Survey, Division of Minerals and Geology, Department of Natural Resources, 2005. https://coloradogeologicalsurvey.org/publications/colorado-coal-directory-2005.

 

“MS-43 Coal Resource Maps of Colorado.” Coal Resources, 1:500,000. Map Series. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 2006. https://coloradogeologicalsurvey.org/publications/coal-resource-maps-colorado.

 

“OF-99-10 Correlation of Producing Fruitland Formation Coals Within the Western Outcrop and Coalbed Methane Leakage on the Southern Ute Reservation.” Coal. Open File Report. Denver, CO: Colorado Geological Survey, Division of Minerals and Geology, Department of Natural Resources, July 31, 1998. https://coloradogeologicalsurvey.org/publications/correlation-fruitland-formation-coals-coalbed-methane-leakage-southern-ute-reservation-colorado.

 

“SP-54 2003 Summary of Coal Resources in Colorado.” Coal Resources. Special Publication. Denver, CO: Colorado Geological Survey, Division of Minerals and Geology, Department of Natural Resources, 2003. https://coloradogeologicalsurvey.org/publications/summary-coal-resources-colorado-2003.

 

Carroll, Christopher J., and Mark A. Bauer. “IS-64 Historic Coal Mines of Colorado.” Coal Mines. Information Series. Denver, CO: Colorado Geological Survey, Division of Minerals and Geology, Department of Natural Resources, 2001. https://coloradogeologicalsurvey.org/publications/historic-coal-mines-colorado.

 

Carroll, Christopher J., David A. Gonzales, Gary L. Gianniny, Karen J. Houck, Nicholas A. Watterson, Tor Stetson-Lee, and Emilee Skyles. “MS-49 Geologic Map and Coal Bed Stratigraphy of the Fruitland Formation in Western Archuleta County, Colorado.” Stratigraphic, 1:12,000. Map Series. Denver, CO: Colorado Geological Survey, Department of Natural Resources, January 2011. https://coloradogeologicalsurvey.org/publications/fruitland-formation-geologic-map-coal-bed-stratigraphy-archuleta-colorado.

 

Carroll, Christopher J., Alexander R. Papp, and Dwight M. Kinnes. “RS-41 Available Coal Resources of the Williams Fork Formation in the Yampa Coal Field, Routt and Moffat Counties, Colorado.” Coal Resources. Resource Series. Denver, CO: Colorado Geological Survey, Division of Minerals and Geology, Department of Natural Resources, 2003. https://coloradogeologicalsurvey.org/publications/coal-resources-williams-fork-yampa-coal-routt-moffat-colorado.

 

Carroll, Christopher J., and Beth L. Widmann. “IS-55 Colorado Coal Directory With Statistics on Electric Generation and Map of Coal Production and Distribution.” Coal Industry. Information Series. Denver, CO: Colorado Geological Survey, Division of Minerals and Geology, Department of Natural Resources, 2000. https://coloradogeologicalsurvey.org/publications/colorado-coal-directory-2000.

 

Carter, Lorna M., ed. RS-10 Proceedings of the Fourth Symposium on the Geology of Rocky Mountain Coal – 1980. Resource Series, RS-10. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1980. https://coloradogeologicalsurvey.org/publications/proceedings-symposium-geology-rocky-mountain-coal-1980.

 

Colorado Geological Survey. “RockTalk V01N3, July 1998 – Coal in Colorado.” RockTalk, July 1998.

 

RockTalk V03N3, July 2000 – Coalbed Methane in Colorado.” RockTalk, July 2000.

 

RockTalk V08N2, Summer 2005 – Colorado Coal.” RockTalk, Summer 2005.

 

Danilchik, Walter, Janet E. Schultz, and Carol M. Tremain. “OF-79-03 Content of Methane in Coal from Four Core Holes in the Raton and Vermejo Formations, Las Animas County, Colorado.” Coalbed Methane. Open File Report. Denver. CO: Colorado Geological Survey, Department of Natural Resources, 1979. https://coloradogeologicalsurvey.org/publications/content-methane-coal-raton-vermejo-formations-las-animas-colorado.

 

Dawson, Louise C., and D. Keith Murray. “RS-03 Colorado Coal Directory and Source Book.” Coal. Resource Series. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1978. https://coloradogeologicalsurvey.org/publications/coal-directory-colorado-1978.

 

Eakins, W. E., C. M. Tremain, R. C. Phillips, and M. L. Morgan. “OF-98-05 Demonstrated Reserve Base for Coal in Colorado – Somerset Coal Field.” Coal. Open File Report. Denver, CO: Colorado Geological Survey, Division of Minerals and Geology, Department of Natural Resources, 1998. https://coloradogeologicalsurvey.org/publications/demonstrated-coal-reserve-base-somerset-field-colorado.

 

Eakins, Wynn. “OF-83-02 Geophysical and Lithological Logs from the 1982 and 1983 Coal Drilling and Coring Program, Castle Rock (1/2×1 Degree) Quadrangle.” Coal Resources. Open File Report. Denver. CO: Colorado Geological Survey, Department of Natural Resources, 1983. https://coloradogeologicalsurvey.org/publications/geophysical-lithological-logs-1982-1983-coal-drilling-coring-program-castle-rock-quadrangle.

 

“OF-86-01 Coal Resources of the Dakota Sandstone, Southwestern Colorado.” Coal Resources. Open File Report. Denver. CO: Colorado Geological Survey, Department of Natural Resources, 1986. https://coloradogeologicalsurvey.org/publications/coal-resources-dakota-sandstone-southwestern-colorado.

 

“RS-27 Coal Resources of the Colorado Springs (1/2° x 1°) Quadrangle, Colorado.” Coal. Resource Series. Colorado Geological Survey, Department of Natural Resources, 1986. https://coloradogeologicalsurvey.org/publications/coal-resources-colorado-springs-quadrangle-colorado.

 

Eakins, Wynn, Carol M. T. Ambrose, David C. Scott, and Dale D. Teeters. “RS-36 Availability of Coal Resources in Colorado: Somerset Quadrangle, West-Central Colorado.” Coal Resources. Resource Series. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1998. https://coloradogeologicalsurvey.org/publications/coal-resources-somerset-quadrangle-colorado.

 

Eakins, Wynn, and Margaret S. Ellis. “RS-25 Coal Resources of the Castle Rock (1/2° x 1°) Quadrangle and Adjacent Area, Colorado.” Coal. Resource Series. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1987. https://coloradogeologicalsurvey.org/publications/coal-resources-castle-rock-quadrangle-colorado.

 

Fender, Hollis B., D. C. Jones, and D. Keith Murray. “Bulletin 41 – Bibliography and Index of Publications Related to Coal in Colorado 1972-1977.” Coal Bibliography. Bulletin. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1978. https://coloradogeologicalsurvey.org/publications/coal-colorado-bibliography-index-1972-1977.

 

Fender, Hollis B., and D. Keith Murray. “OF-78-02 Data Accumulation on the Methane Potential of the Coal Beds of Colorado.” Coal Bed Methane. Open File Reports. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1978. https://coloradogeologicalsurvey.org/publications/data-accumulation-methane-potential-coal-beds-colorado.

 

Goolsby, Steven M., and Nir Bhao Singh Reade. “MS-12 Map of Licensed Coal Mines in Colorado as of June 1, 1978.” Coal Mines, 1:500,000. Map Series. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1978. https://coloradogeologicalsurvey.org/publications/map-licensed-coal-mines-colorado-1978.

 

Goolsby, Steven M., Nirbhao Singh Reade, and D. Keith Murray. “RS-07 Evaluation of Coking Coals in Colorado.” Resource Series. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1979. https://coloradogeologicalsurvey.org/publications/evaluation-coking-coals-colorado.

 

Hardie, John K., and Neely H. Bostick. “Bulletin 53 – Clastic Dikes Intruding Cretaceous Coals of Western Colorado.” Bulletin. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1999. https://coloradogeologicalsurvey.org/publications/clastic-dikes-intruding-cretaceous-coals-western-colorado.

 

Hardie, John K., and Jonathan M. Zook. “OF-97-05 Geologic Map and Coal Measures of the Axial Quadrangle, Moffat and Rio Blanco Counties, Colorado.” Coal, 1:24,000. Open File Report. Denver, CO: Colorado Geological Survey, Division of Minerals and Geology, Department of Natural Resources, 1997. https://coloradogeologicalsurvey.org/publications/geologic-map-coal-measures-axial-quadrangle-moffat-rio-blanco-colorado.

 

Hatton, Tom, and J. E. Turney. “IS-22 Annotated Bibliography of Subsidence Studies over Abandoned Coal Mines in Colorado.” Coal. Information Series. Denver, CO: Colorado Geological Survey, Department of Natural Resources, June 1989. https://coloradogeologicalsurvey.org/publications/bibliography-subsidence-studies-abandoned-coal-mines-colorado.

 

Hemborg, H. Thomas. “RS-33 Spanish Peak Field, Las Animas County, Colorado: Geologic Setting and Early Development of a Coalbed Methane Reservoir in the Central Raton Basin.” Coal Bed Methane. Resource Series. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1998. https://coloradogeologicalsurvey.org/publications/spanish-peak-field-las-animas-geologic-coalbed-methane-reservoir-raton-basin-colorado.

 

Hodgson, Helen E., ed. RS-04 Proceedings of the Second Symposium on the Geology of Rocky Mountain Coal — 1977. Resource Series, RS-04. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1978. https://coloradogeologicalsurvey.org/publications/proceedings-second-symposium-geology-rocky-mountain-coal-1977.

 

Holt, Richard Dexter. “Bulletin 34A – Bibliography, Coal Resources in Colorado.” Coal Bibliography. Bulletin. Denver, Co: Colorado Geological Survey, Department of Natural Resources, 1972. https://coloradogeologicalsurvey.org/publications/bibliography-coal-resources-colorado.

 

Hornbaker, A. L., R. D. Holt, and D. Keith Murray. “SP-09 1975 Summary of Coal Resources in Colorado.” Coal Resources. Special Publication. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1976. https://coloradogeologicalsurvey.org/publications/coal-resources-colorado.

 

Hynes, Jeffrey L. SP-31 Proceedings of the 1985 Conference on Coal Mine Subsidence in the Rocky Mountain Region. Special Publications, SP-31. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1986. https://coloradogeologicalsurvey.org/publications/proceedings-conference-coal-mine-subsidence-rocky-mountain-region-1985.

 

“IS-10 Colorado Coal Analyses, 1976-1979.” Coal. Information Series. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1981. https://coloradogeologicalsurvey.org/publications/colorado-coal-analyses-1976-1979.

 

Jones, D. C. “IS-01 Coal Mines and Coal Fields of Colorado.” Coal Resources, 1:500,000. Information Series. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1976. https://coloradogeologicalsurvey.org/publications/coal-mines-fields-colorado.

 

“MS-08 Licensed Coal Mines in Colorado.” Coal Mines, 1:500,000. Map Series. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1977. https://coloradogeologicalsurvey.org/publications/licensed-coal-mines-colorado.

 

Jones, D. C., and D. Keith Murray. “IS-02 Coal Mines of Colorado Statistical Data.” Coal Mines. Information Series. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1976. https://coloradogeologicalsurvey.org/publications/coal-mines-colorado-statistical-data.

 

Jones, D. C., Janet E. Schultz, and D. Keith Murray. “MS-09 Coal Resources and Development Map of Colorado.” Coal Resources, 1:500,000. Map Series. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1978. https://coloradogeologicalsurvey.org/publications/coal-resource-development-map-colorado.

 

Jones, David C. “OF-76-01 Active/Licensed Coal Mines of Colorado.” Coal Mines, 1:500,000. Open File Reports. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1976. https://coloradogeologicalsurvey.org/publications/active-licensed-coal-mines-colorado.

 

“OF-78-01 First Annual Report, Evaluation of Coking Coal Deposits in Colorado.” Coal Mines. Open File Reports. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1977. https://coloradogeologicalsurvey.org/publications/evaluation-coking-coal-deposits-colorado.

 

Kaiser, W. R., A. R. Scott, D. S. Hamilton, Roger Tyler, R. G. McMurry, Naijiang Zhou, and Carol M. Tremain. “RS-30 Geologic and Hydrologic Controls on Coalbed Methane: Sand Wash Basin, Colorado and Wyoming.” Coalbed Methane. Resource Series. Denver, CO: Colorado Geological Survey, Division of Minerals and Geology, Department of Natural Resources, 1993. https://coloradogeologicalsurvey.org/publications/geologic-hydrologic-controls-coalbed-methane-sand-wash-basin-colorado-wyoming.

 

Kelso, Bruce S. “OF-82-04 Southern Ute / Department of Energy Coal Bed Methane Test Wells.” Coal Bed Methane. Open File Report. Denver. CO: Colorado Geological Survey, Department of Natural Resources, 1982. https://coloradogeologicalsurvey.org/publications/southern-ute-department-energy-coalbed-methane-test-wells.

 

Kelso, Bruce S., Steven M. Goolsby, and Carol M. Tremain. “OF-80-02 Deep Coal Bed Methane Potential of the San Juan River Coal Region, Southwestern Colorado.” Coalbed Methane. Open File Report. Denver. CO: Colorado Geological Survey, Department of Natural Resources, 1980. https://coloradogeologicalsurvey.org/publications/deep-coal-bed-methane-potential-san-juan-river-region-southwestern-colorado.

 

Kelso, Bruce S., L. R. Ladwig, and Linda Sitowitz. “MS-15 Directory of Permitted Colorado Coal Mines, 1981.” Coal Mines, 1:500,000. Map Series. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1981. https://coloradogeologicalsurvey.org/publications/map-permitted-coal-mines-colorado-1981.

 

Kirkham, Robert M. “OF-78-08 Location Map of Drill Holes Used for Coal Evaluation in the Denver and Cheyenne Basins, Colorado.” Coal Resources, 1:250,000. Open File Report. Denver. CO: Colorado Geological Survey, Department of Natural Resources, 1978. https://coloradogeologicalsurvey.org/publications/location-map-drill-holes-coal-evaluation-denver-cheyenne-basins-colorado.

 

“OF-78-09 Coal Mines and Coal Analyses of the Denver and Cheyenne Basins, Colorado.” Coal Resources. Open File Report. Denver. CO: Colorado Geological Survey, Department of Natural Resources, 1978. https://coloradogeologicalsurvey.org/publications/coal-mines-coal-analysis-denver-cheyenne-basins-colorado.

 

Kirkham, Robert M., and L. R. Ladwig. “RS-05 Coal Resources of the Denver and Cheyenne Basins, Colorado.” Coal. Resource Series. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1979. https://coloradogeologicalsurvey.org/publications/coal-resources-denver-cheyenne-basins-colorado.

 

Kirkham, Robert M., and William J. O’Leary. “IS-13 Chemical Analyses of Water Wells in Selected Strippable Coal and Lignite Areas, Denver Basin, Colorado.” Water. Information Series. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1980. https://coloradogeologicalsurvey.org/publications/chemical-analyses-water-wells-strippable-coal-lignite-denver-basin-colorado.

 

Kuhn, Edwin A. “RS-29 Directory and Statistics of Colorado Coal Mines with Distribution and Electric Generation Map, 1989.” Coal Mines. Resource Series. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1990. https://coloradogeologicalsurvey.org/publications/coal-mines-electric-generation-map-colorado-1989.

 

Ladwig, L. R. “SP-23 Summary of Coal Resources in Colorado.” Coal Industry. Special Publication. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1981. https://coloradogeologicalsurvey.org/publications/coal-resources-colorado-1981.

 

Matthews, Vincent, ed. SP-51 Coal and Coalbed Methane in Colorado CD. Special Publications, SP-51. Denver, CO: Colorado Geological Survey, Division of Minerals and Geology, Department of Natural Resources, 2003. https://coloradogeologicalsurvey.org/publications/coal-coalbed-methane-colorado.

 

McMurry, Ronald G., and Roger Tyler. “OF-97-07 Genetic-Stratigraphic Cross Section of the Coal-Bearing Williams Fork Formation.” Coal. Open File Report. Denver, CO: Colorado Geological Survey, Division of Minerals and Geology, Department of Natural Resources, 1997. https://coloradogeologicalsurvey.org/publications/stratigraphic-structural-cross-sections-coal-williams-fork-formation-mesaverde-colorado.

 

Murray, D. Keith, ed. RS-01 Geology of Rocky Mountain Coal: Proceedings of the 1976 Symposium. Resource Series, RS-01. Denver, CO: Colorado Geological Survey, Division of Minerals and Geology, Department of Natural Resources, 1976. https://coloradogeologicalsurvey.org/publications/geology-rocky-mountain-coal-symposium-1976.

 

“SP-13 1979 Summary of Coal Resources in Colorado.” Coal Resources. Special Publication. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1979. https://coloradogeologicalsurvey.org/publications/summary-coal-resources-colorado-1979.

 

Pearl, Richard Howard. “SP-03 1972 Summary of Coal Resources in Colorado.” Coal Resources. Special Publication. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1972. https://coloradogeologicalsurvey.org/publications/coal-resources-colorado-1972.

 

Rushworth, Peter. “OF-83-01 Bibliography Coal Resources San Juan River Region, Colorado.” Open File Report. Denver. CO: Colorado Geological Survey, Department of Natural Resources, 1983. https://coloradogeologicalsurvey.org/publications/bibliography-coal-resources-san-juan-river-colorado.

 

“OF-83-10 Programmable Calculator Solutions for Coal Quality Determinations.” Coal Resources. Open File Report. Denver. CO: Colorado Geological Survey, Department of Natural Resources, 1983. https://coloradogeologicalsurvey.org/publications/programmable-calculator-solutions-coal-quality-determinations.

 

“OF-84-01 Bibliography Coal Resources Uinta Coal Region, Colorado.” Open File Report. Denver. CO: Colorado Geological Survey, Department of Natural Resources, 1984. https://coloradogeologicalsurvey.org/publications/bibliography-coal-resources-uinta-region-colorado.

 

“OF-84-17 Bibliography Coal Resources North, Middle, and South Park Coal Regions, Colorado.” Open File Report. Denver. CO: Colorado Geological Survey, Department of Natural Resources, 1984. https://coloradogeologicalsurvey.org/publications/bibliography-coal-resources-north-middle-south-park-coal-fields-colorado.

 

“SP-24 Analysis of the Colorado Coal Industry.” Coal Industry. Special Publication. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1984. https://coloradogeologicalsurvey.org/publications/analysis-colorado-coal-industry.

 

Rushworth, Peter, Bruce D. Haefner, Jeffrey L. Hynes, and Randall K. Streufert. “IS-26 Reconnaissance Study of Coal Fires in Inactive Colorado Coal Mines.” Coal Fires. Information Series. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1989. https://coloradogeologicalsurvey.org/publications/coal-fires-inactive-colorado-coal-mines.

 

Rushworth, Peter, Bruce S. Kelso, Michael E. Brownfield, and Edward A. Johnson. “IS-25 Selected References on the Geology and Coal Resources of Central and Western Colorado Coal Fields and Regions.” Coal. Information Series. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1988. https://coloradogeologicalsurvey.org/publications/references-geology-resources-central-western-colorado-coal-field-region.

 

Rushworth, Peter, Bruse S. Kelso, and L. R. Ladwig. “MS-23 Map, Directory, and Statistics of Permitted Colorado Coal Mines, 1983.” Coal Mine, 1:500,000. Map Series. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1983. https://coloradogeologicalsurvey.org/publications/map-directory-statistics-permitted-coal-mines-colorado-1983.

 

Rushworth, Peter, and L. R. Ladwig. “SP-25 Forecast of Colorado Coal Industry Production and Employment 1984 to 2004.” Coal Production. Special Publication. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1984. https://coloradogeologicalsurvey.org/publications/forecast-colorado-coal-industry-production-employment-1984-2004.

 

Schultz, Janet E., and Wynn Eakins. “RS-38 Availability of Coal Resources in Colorado: Somerset Coal Field, West-Central Colorado.” Coal Resources. Resource Series. Denver, CO: Colorado Geological Survey, Division of Minerals and Geology, Department of Natural Resources, 2000. https://coloradogeologicalsurvey.org/publications/coal-resources-somerset-field-colorado.

 

Scott, Andrew R. “OF-94-02 Coalbed Gas Composition, Upper Cretaceous Fruitland Formation, San Juan Basin, Colorado and New Mexico.” Coalbed Gas Composition. Open File Report. Denver, CO: Colorado Geological Survey, Division of Minerals and Geology, Department of Natural Resources, 1994. https://coloradogeologicalsurvey.org/publications/coalbed-gas-composition-cretaceous-fruitland-san-juan-basin-colorado-new-mexico.

 

S.S. Papadopulos & Associates, Inc. and Colorado Geological Survey. “WAT-2008-01 – Coalbed Methane Stream Depletion Assessment Study – Piceance Basin, Colorado.” Water Resources. Denver, CO: Colorado Geological Survey, Department of Natural Resources, April 2008. https://coloradogeologicalsurvey.org/publications/cbm-piceance-basin-colorado/.

 

“WAT-2008-02 – Coalbed Methane Stream Depletion Assessment Study – Raton Basin, Colorado.” Water Resources. Denver, CO: Colorado Geological Survey, Department of Natural Resources, March 2008. https://coloradogeologicalsurvey.org/publications/cbm-raton-basin-colorado/.

 

S.S. Papadopulos & Associates, Inc. and Colorado Geological Survey. “WAT-2006-01 – Coalbed Methane Stream Depletion Assessment Study – Northern San Juan Basin, Colorado.” Water Resources. Denver, CO: Colorado Geological Survey, Department of Natural Resources, February 2006. https://coloradogeologicalsurvey.org/publications/cbm-san-juan-basin-colorado/.

 

Tremain, C. M., A. L. Hornbaker, R. D. Holt, D. Keith Murray, and L. R. Ladwig. “SP-36 1990 Summary of Coal Resources in Colorado.” Coal Resources. Special Publication. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1990. https://coloradogeologicalsurvey.org/publications/summary-coal-resources-colorado-1990.

 

“SP-41 1996 Summary of Coal Resources in Colorado.” Coal Resources. Special Publication. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1996. https://coloradogeologicalsurvey.org/publications/summary-coal-resources-colorado-1995.

 

Tremain, Carol M. “IS-32 Coalbed Methane Development in Colorado, September 1990.” Coal Bed Methane. Information Series. Denver, CO: Colorado Geological Survey, Department of Natural Resources, September 1990. https://coloradogeologicalsurvey.org/publications/coalbed-methane-development-september-1990-aapg-denver-colorado.

 

“MS-19 The Coal Bed Methane Resources of Colorado.” Coal Bed Methane, 1:500,000. Map Series. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1983. https://coloradogeologicalsurvey.org/publications/coal-bed-methane-resources-colorado.

 

“OF-80-04 The Coal Bed Methane Potential of the Raton Mesa Coal Region, Raton Basin, Colorado.” Coalbed Methane. Open File Report. Denver. CO: Colorado Geological Survey, Department of Natural Resources, 1980. https://coloradogeologicalsurvey.org/publications/coal-bed-methane-potential-raton-basin-colorado.

 

“OF-82-01 The Coal Bed Methane Potential of the Piceance Basin, Colorado.” Coal Bed Methane. Open File Report. Denver. CO: Colorado Geological Survey, Department of Natural Resources, 1982. https://coloradogeologicalsurvey.org/publications/coal-bed-methane-potential-piceance-basin-colorado.

 

Tremain, Carol M., Wynn Eakins, Janet E. Schultz, and Bruce S. Kelso. “IS-58 Colorado Coal Quality Data.” Coal. Information Series. Denver, CO: Colorado Geological Survey, Division of Minerals and Geology, Department of Natural Resources, 2001. https://coloradogeologicalsurvey.org/publications/coal-quality-data-colorado.

 

Tremain, Carol M., and James Toomey. “OF-81-04 Coal Bed Methane Desorbtion Data.” Coal Bed Methane. Open File Report. Denver. CO: Colorado Geological Survey, Department of Natural Resources, 1983. https://coloradogeologicalsurvey.org/publications/coal-bed-methane-desorption-data-1981.

 

Turney, J. E., Al Amundson, Celia Greenman, and Bruce K. Stover. “SP-26 Subsidence Above Inactive Coal Mines: Information for the Homeowner.” Special Publication. Denver, CO: Department of Natural Resources; Colorado Geological Survey; and Colorado Division Of Reclamation, Mining & Safety, 2009 1985. https://coloradogeologicalsurvey.org/publications/subsidence-inactive-coal-mines-homeowner-information.

 

Tyler, Roger, and Ronald G. McMurry. “OF-95-02 Genetic Stratigraphy, Coal Occurrence and Regional Cross Section of the Coal-Bearing Williams Fork Formation, Mesaverde Group, Piceance Basin, Northwestern Colorado.” Coal. Open File Report. Denver, CO: Colorado Geological Survey, Division of Minerals and Geology, Department of Natural Resources, 1995. https://coloradogeologicalsurvey.org/publications/genetic-stratigraphy-regional-cross-section-coal-bearing-williams-fork-mesaverde-piceance-basin-colorado.

 

Tyler, Roger, Naijiang Zhou, R. G. McMurry, M. L. W. Jackson, and C. M. Tremain. “IS-35 Selected References Related to Coalbed Methane in the Greater Green River, Piceance, Powder RIver, Raton, and San Juan Basins.” Bibliography. Information Series. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1992. https://coloradogeologicalsurvey.org/publications/references-coalbed-methane-green-river-piceance-powder-river-raton-san-juan-basins.

 

Wray, Laura, and Nicole V. Koenig. “OF-01-17 The Coalbed Methane Potential in the Upper Cretaceous to Early Tertiary Laramie and Denver Formations, Denver Basin, Colorado.” Coal Bed Methane. Open File Report. Denver, CO: Colorado Geological Survey, Division of Minerals and Geology, Department of Natural Resources, 2001. https://coloradogeologicalsurvey.org/publications/coalbed-methane-potential-cretaceous-tertiary-laramie-formations-denver-basin-colorado.

 

Zook, Jonathan M., and Carol M. Tremain. “RS-32 Directory and Statistics of Colorado Coal Mines with Distribution and Electric Generation Map, 1995-96.” Coal Mines. Resource Series. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1997. https://coloradogeologicalsurvey.org/publications/statistics-coal-mine-electric-generation-map-colorado-1995-96.

Media

Media

Coal mining operations at the ColoWyo Coal Mine, Moffat and Rio Blanco Counties. Photo credit: Mike O'Keeffe (CGS)
Excavator working Wadge coal seam, a year before the Yoast Mine, 25 miles west of Steamboat Springs, closed in 2006. Photo credit: Chris Carroll for the CGS.
Excavator working Wadge coal seam, a year before the Yoast Mine, 25 miles west of Steamboat Springs, closed in 2006. Photo credit: Chris Carroll for the CGS.
The North Fork of the Gunnison River flows past the stockpile and loadout facilities for Arch Coal's West Elk Mine in Gunnison County, Colorado. June 2004. Photo credit: Chris Carroll for the CGS.
The North Fork of the Gunnison River flows past the stockpile and loadout facilities for Arch Coal's West Elk Mine in Gunnison County, Colorado. June 2004. Photo credit: Chris Carroll for the CGS.
Mine and tipple, Huerfano Coal Company, Ludlow Mine, Ludlow, Colorado, June 1946. Photo credit: Russell Lee.
Mine and tipple, Huerfano Coal Company, Ludlow Mine, Ludlow, Colorado, June 1946. Photo credit: Russell Lee.
Seneca II-W coal mine, Wolf Creek pit with excavators, Routt County, Colorado, October 2005. Photo credit: Chris Carroll for the CGS.
Seneca II-W coal mine, Wolf Creek pit with excavators, Routt County, Colorado, October 2005. Photo credit: Chris Carroll for the CGS.