Since the mid- to late 1990s, the number and size of coal mines known as mountaintop removal mines increased dramatically in parts of Virginia, West Virginia, Pennsylvania, and Kentucky. The final step in processing this coal creates sludge that contains coal dust, sediment, and possibly heavy metals and chemicals. Mine operators contain the coal sludge in nearby valleys, behind huge earthen dams known as valley fills.
Mountaintop removal mining dramatically changes the topography across thousands of acres. Mountaintop removal mining alters this topography by reducing the elevation of the ridge lines, flattening out the steep slopes, and also by filling in hollows and stream beds with the excess rock and dirt that once topped the mountains.
The colors may not look as brilliant as the reds and golds you would see on the ground, but even from space, the difference between the summer and fall attire of the U.S. Mid-Atlantic is dramatic.