COAL: Ancient Gift Serving Modern Man
27 Coal-Mining StatesCoal Areas of the United States and Table of Production By State
Although 90 percent of the country's coal reserves are concentrated in 10 states, coal in mined in 27 states and can be found in even more. Montana has the most coal, 25 percent of demonstrated reserves. Wyoming, third among states with the most coal, is first in coal output, accounting for 18 percent of annual production.
U.S. coal reserves contain 12 times as much energy as all the oil in Saudi Arabia! A brief look at some numbers explains why coal is the country's most abundant and important energy resource.
According to the United States Geological Survey, we have 1.7 trillion tons of identified coal resources -- coal for which geological evidence and engineering studies provide reliable information about location, rank, quality, and quantity. (Geologists recognize that more coal deposits are likely to be discovered in the future, so they estimate total coal resources could amount to 4 trillion tons.)
Much of the coal we know about cannot be mined today, because it would be too costly or existing technology doesn't allow it. It may be too deep, for example, or the quality may not meet current needs. So to be realistic, experts estimate that 472 billion tons of that coal are potentially recoverable. This is called the demonstrated reserve base.
Mining techniques leave a good deal of coal in place, so the amount of coal that experts estimate actually can be mined is called the recoverable reserve base. It amounts to an estimated 267 billion tons -- 29 percent of the entire world's recoverable coal!