By the end of 2020, the number of producing coal mines in the United States fell to 551 mines, the lowest number since U.S. coal production peaked in 2008. In 2020, 40 coal mines were opened or reactivated, and 151 mines were idled or closed. This overall decrease resulted in an 18% annual decline in the total number of producing coal mines from 2019 and a 62% decline since 2008. Shutting down less efficient mines while adding relatively few new mines and reactivating few idled mines resulted in the reduction in 2020.