Coal became Utah's state rock by a decree from the Utah State Legislature in 1991. It was proposed by Representative Mike
Dmitrich of Price as a result of a school project in Carbon County. It has been an important part of Utah's history, and now
is recognized and given a place of honor among the state symbols.
Coal is called a fossil fuel (because it contains the remains of once-living plants and animals that can be burned to release
energy), a burnable carbonaceous rock (a rock that contains organic matter and is high in carbon and other elements), and is
also considered a mineral of organic origin due to its containing has various amounts of mineral matter. It is a very special,
very valuable rock that happens to be abundant in Utah.
Coal formation is an ongoing process, and occurs when bacteria break down the plant material and convert it to peat by
removing oxygen and hydrogen.
The peat is then buried by sediment and more plant material, raising its temperature and pressure. As the peat compresses,
water and methane gas are forced out, leaving an increasing proportion of carbon. With increasing heat and pressure the peat
is converted successively into one of the four types of coal:
•lignite: (A brownish-black coal with generally high moisture and ash content, and the lowest carbon content and
•subbituminous: (A dull black coal with a higher heating value)
•bituminous: (A soft, intermediate grade of coal that is the most common and widely used in the United States, and is
relatively high in potential heat production units (BTUs))
•anthracite: (The hardest type of coal, consisting of nearly pure carbon. Anthracite has the highest heating value and
lowest moisture and ash content)
The greater the heat and pressure, the harder the coal. Most of the coal mined in Utah is bituminous.
Coal is mined by two main methods - surface or strip mining and underground or deep mining. The choice of method is
largely determined by the geology of the coal deposit.
When the coal is close to the surface, heavy earth-moving equipment can be used to scrape the earth and rock off the
coal, scoop it out and replace the excavated earth. The area can then be revegetated (a process known as reclamation),
and is a way of mining that permits recovery of 90 percent or more of the coal in the area.
Underground mining is needed to extract coal lying deep beneath the Earth's surface or in seams exposed on hillsides.
Openings are drilled into the coal bed which transport workers and equipment, to send coal to the surface, and to circulate
air in the mine. Nearly all of Utah's coal must be obtained from underground mines.
Coal is the major fuel source for electric power generation worldwide. It is burned in power plants to produce heat and
electricity. More than half of the total world coal production provides around 39% of the world's electricity. Coal is also
a major component in iron and steel production, aiding in almost 70% of total global steel production.
Coal will continue to be an important primary energy resource, just like oil and gas, and other non-fossil fuels, as it is
far more plentiful than domestic oil or natural gas, making up about 95 percent of America's fossil energy reserves.
Utah has eighteen recognized coal fields (in 17 of its 29 counties) which contain an estimated 39 billion tons of coal.
Coal mining is primarily concentrated in Emery and Carbon Counties, and the three most important coal fileds in the state
are The Book Cliffs, the Wasatch Plateau and Kaiparowits.
Utah Mine Locations
Utah's coal industry and railroads
Utah Mining Association
History of Coal Mining in Utah
Old King Coal—A Colorful Story
USGS - Coal as an Energy Source
Geologic Assessment of Coal in the Colorado Plateau
Colorado and Utah Coal Train Pictures