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About Wyoming

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Wyoming’s vermiculite processing plants also put workers in danger of developing mesothelioma or other serious illnesses, such as asbestosis and lung cancer. Contaminated materials from the W.R. Grace mine in Libby, Montana, were shipped to four vermiculite processing plants in Wyoming. More than 8,851 tons of Libby’s asbestos-tainted vermiculite were “exfoliated” by refinery workers at these plants, where they were responsible for transporting, heating, packaging and shipping the mineral.

Refinery workers at these plants transported and heated 8,851 tons of Libby’s asbestos-tainted vermiculite in a process known as exfoliation. They also packaged and shipped the mineral.

Occupations at Risk

Wyoming’s abundant petroleum sources made it a hotspot for refineries. Workers at these refineries often worked with high-temperature machines that were insulated with asbestos. Construction workers who repaired these facilities may have come in contact with contaminated tiles, panels or insulation.

Power station workers were also at an elevated risk for inhaling asbestos. Refineries and power plants were often built using the mineral or were home to various forms of asbestos insulation, and the workers faced exposure threats when fixing damaged machinery or renovating the buildings. Mesothelioma Guide

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Treatment Centers near Wyoming

University of Colorado Cancer Center

University of Colorado Cancer Center

1665 Aurora Court, Aurora, CO 80045

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Nevada Comprehensive Cancer Center

Nevada Comprehensive Cancer Center

3730 S. Eastern Avenue, Las Vegas, NV, 89169

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Mayo Clinic Arizona

Mayo Clinic Arizona

13400 East Shea Blvd, Scottsdale, AZ 85259

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Mayo Clinic Minnesota

Mayo Clinic Minnesota

200 First Street SW Rochester, MN 55905

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Arizona Cancer Center

Arizona Cancer Center

3838 North Campbell Avenue, Tucson, AZ 85719

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OHSU Knight Cancer Institute

OHSU Knight Cancer Institute

3181 SW Sam Jackson Park Rd, Portland, OR 97239

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Jobsites with Known Exposure


Commercial asbestos mining in Wyoming peaked between 1905 and 1921. Casper Mountain was the largest such mine in the state, producing fibers of more than an inch in length. More than half of the material in the serpentine deposits at Casper Mountain was asbestos.

Other deposits included:

  • Brown Bear
  • Smith Creek
  • Laramie Mountain
  • Fire King
  • Beaver Creek

The Fire King deposit specialized in producing chrysotile blocks for chimneys, while Smith Creek and Casper Mountain’s asbestos was primarily shipped to flooring manufacturers.


Frontier Oil and Sinclair Oil are two prominent oil refineries in Wyoming. The refineries, both built prior to the 1970s, used asbestos during construction. Over the decades, the workplaces exposed countless individuals to the hazardous fiber.

Other oil refineries in Wyoming included:

  • Consumer Oil
  • Fargo Oil
  • Continental Oil
  • Mutual Oil Company

Coal refineries were also scattered across the state. Like oil refineries, these facilities were home to large quantities of asbestos-insulated equipment.

Vermiculite refineries were also a significant part of Wyoming’s industrial economy. Four refineries received shipments of Libby’s contaminated vermiculite. Workers at these refineries handled as many as 221 shipments of vermiculite from the W.R. Grace mine.

Wyoming's vermiculite refineries were located in:

  • Cody
  • Lovell
  • Burlington
  • Thermopolis

Power Plants

Black Hills Power’s facility in Osage was constructed with asbestos insulation around its boilers. Anyone who worked for the company prior to 1993 may have been exposed to the toxic mineral. By 1993, however, the company had completed an abatement project. Although some encapsulated asbestos was left in place, the facility was deemed safe.

Similarly, PacifiCorp‘s Dave Johnston Power Plant was built with asbestos insulation surrounding the boiler machinery. In 2007, the company began installing air pollution control equipment to help reduce the risk of exposure to various contaminants.

University of Wyoming

As with many private buildings constructed before the 1980s, the University of Wyoming was built with contaminated materials. In 2009 the college was issued a violation by the Department of Environmental Quality for failing to conduct asbestos inspections and remove asbestos-contaminated materials before demolishing several campus buildings. As a result, asbestos-containing materials were scattered during the demolition.

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Last Modified October 25, 2018


Matt Mauney is an award-winning journalist with nearly a decade of professional writing experience. He joined in 2016, and he spends much of his time reading, analyzing and reporting on mesothelioma research articles to ensure people in the mesothelioma community know the latest medical advancements. Prior to joining, Matt was a reporter at the Orlando Sentinel. Matt also edits some of the pages on the website. He also holds a certificate in health writing from the Centers for Disease Control and Prevention.

Walter Pacheco, Managing Editor at
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8 Cited Article Sources

  1. Beckwith, R. H. (1939). Asbestos and chromite deposits of Wyoming. Geological Survey of Wyoming. : Retrieved from:
  2. Centers for Disease Control - Malignant Mesothelioma Mortality, Untied States, 1999-2005. (2009, April 22). : Retrieved from:
  3. PacifiCorp Energy - Dave Johnston Steam Electric Plant. (2007, November 9). : Retrieved from:
  4. Securities and Exchange Commission - Black Hills Corp. (1994). : Retrieved from:
  5. State of Wyoming Department of Environmental Quality - Notice of Violation. Retrieved from: Retrieved from:
  6. State of Wyoming Department of Environmental Quality - Notification Instructions. : Retrieved from:
  7. Van Gosen, B. (2007). Reported historic asbestos mines, historic asbestos prospects and natural asbestos occurrences in the Rocky Mountain States. US Department of the Interior. : Retrieved from:
  8. Centers for Disease Control and Prevention, National Center for Health Statistics. (2015, January). Underlying Cause of Death 1999-2013 on CDC WONDER Online Database. : Retrieved from:

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