In order to do mountain top removal, there needs to be flat lying coal beds that underlie an overburden of less than 200 ft thick and these units need to be part of a "hill and holler" topography. Over that thickness ,and its uneconomical to mine and if its not flat lying and not in a hill and holler topo, youd do strip mining. West Virginia, Kentucky, Wyoming and Montana have the most areas that one could do removal. Even Montana is mostly a strip mining area .
Mt Top removal is destructive mining since thye amount of coal is usually small for the damage done. The Bush administration tried to denut any of the last regs that Clinton had denutted earlier (Both admins were not friends of the environment no matter what anyone says)