The coalbed thickness of just over half of coal produced in the U.S. was over 120 inches (300cm), and much of this can be reached with surface mining. This explains why coal has been a reliable energy source, even before the development of advanced mining techniques. The most famous coal mines are in West Virginia, but Wyoming is by far the leading U.S. state in coal production, and Pennsylvania has the highest number of coal mines. Overall, the number of active coal mines is has been declining since 2008.
The coal industry is decreasing in profitability, as seen in the decrease of market capitalization of the leading coal companies in the U.S. The leading company, Peabody Energy, had a slight increase in revenue in 2017, as did Arch Coal, but many think that this is a short-term trend due to a change in the U.S. political environment.
Coal mining employees in the U.S. are overwhelmingly men without a university degree. In spite of the lack of post-secondary education, they earn an average salary of 84,000 U.S. dollars per year. However, following production trends, there are fewer coal-mining jobs, particularly in the Appalachian region, with a slight increase in 2017. The highest number of jobs are in West Virginia, with more underground jobs. As a result of fewer surface mines, tens of thousands of acres are reclaimed from coal mining each year.