1. Chart showing lithology, mineralogy, and paleontology of the Pennsylvanian Hermosa Group at Hermosa Mountain, La Plata County, Colorado Author/Creator: Geological Survey (U.S.) Publication/Creation: Denver, CO : For sale by U.S. Geological Survey Information Services Format: Map Access & Availability: Loading
2. Revised correlation chart of coal beds, coal zones, and key stratigraphic units in the Pennsylvanian rocks of eastern Kentucky Author/Creator: Geological Survey (U.S.) Publication/Creation: Denver, CO : For sale by Map Distribution Format: Map Access & Availability: Loading