According to preliminary stats compiled from MSHA, PRB coal production for Q4 2018 was 84 million tons (336 million tons annualized). As a comparison, Q3 2018 production was 87 million tons or 346 million annualized. Full year 2018 PRB coal production ended up at 324 million tons. PRB production during 2017 was 334 million tons. Source: John T. Hanou