This paper explores methane content and emissions associated with mining Powder River Basin (PRB) coals, a Western, Sub-Bituminous coal. Both coal methane content and specific emissions from mining are explored. Methane emissions resulting from the release of methane trapped in coal beds can have a significant impact on the life cycle greenhouse gas (GHG) emissions associated with coal production. These emissions vary dramatically by coal rank, specific seam, and seam depth and thickness. This document is part of the Office of Systems, Analyses, and Planning's Quality Guidelines for Energy Systems Studies (QGESS) series.