Coal exists in the mountains of Appalachia like layers in a cake, with solid rock between the layers. A traditional mine is made of tunnels in the earth created by taking out the coal. But in order to prevent a collapse of the mountain, sections of coal are left untouched and in the upper reaches of the mountains, the higher layers are often not mined at all.
The coal industry figured out that if they could just REMOVE the mountain from the top, exposing the coal, they could extract it all - cheaply, and with better safety standards for miners. So.....
Step 1 - Clear cut the trees. Here, natures bounty of high and low-growth vegetation, with the rich diversity of the temperate forest and understory, is simply removed. It is supposed to be "harvest" but is almost always simply cut, piled, and pushed off the steep slopes into the valleys below.
Step 2 - Blasting. Millions of tons of explosives are set deep within the layer of rock that sits above the coal seam. This rock is BLASTED. (see the trailer for a visual).
Step 3 - Valley Fill - The loose rock is disposed of, pushed off the steep slopes into the valleys below and compacted into what is called a "valley fill" - a terraced wall of compacted earth with little structural integrity. Often a "drag line" is employed to move large sections of earth with its huge shove, the size of a large home.
Step 4 - Coal harvest - the exposed coal seam is scooped up with bulldozers and carted off for chemical processing at a nearby plant.
Step 5 - Blasting. The next layer of rock now needs to be removed and the process begins again.
Thus, minimal labor results in maximum coal extraction. Unfortunately, it is also maximum damage to the environment. Today, about 40% of the coal extracted in West Virginia is mined in this manner...and growing.