Wyoming coal is subbituminous, low in ash and low in sulfur compared with other U.S. coals, particularly those in the eastern U.S. The Btu content (heat value) ranges from 8,000 to 11,000 with most around 8,500. The ash ranges from 4.5% to 9% averaging around 5%. The sulfur ranges from 0.2% to 0.7% averaging around 0.3%.