The Appalachian Mountains contain major deposits of anthracite coal as well as bituminous coal. In the folded mountains the coal is in metamorphosed form as anthracite, represented by the Coal Region of northeastern Pennsylvania. The bituminous coal fields of western Pennsylvania, western Maryland, southeastern Ohio, eastern Kentucky, southwestern Virginia, and West Virginia contain the sedimentary form of coal. The mountain top removal method of coal mining, in which entire mountain tops are removed, is currently threatening vast areas and ecosystems of the Appalachian Mountain region.