Types of Mines
There are two types of mines in Pennsylvania - Surface Mines and Underground Mines.
Surface mines, or strip mines, are large pits where dirt and rock are removed to expose the minerals. Limestone and other non-coal surface mines are often called Quarries. Underground mines are large tunnels that are dug deep into the ground to reach minerals that are too far underground to be reached from surface mines. Underground mines in Pennsylvania can be hundreds of feet deep.