Wyoming possesses the largest coal reserves and consistently ranks as the single largest coal-producing state in the United States by a massive margin. This dominance is anchored by the prolific Powder River Basin, where thick, shallow, low-sulfur sub-bituminous coal seams are extracted via highly efficient surface mining operations. These massive mines supply a substantial portion of the coal used by domestic electric power generating stations across the country, keeping Wyoming far ahead of other historic coal-mining states in terms of total annual tonnage recovered.