Mining has played an important role in the development of the world. In the past, the discovery of minerals such as gold and silver resulted in population shifts and economic growth. Extraction of minerals and coal continues to provide the foundation for local economies in some parts of the country. Products of this industry are used as inputs for consumer goods, processes, and services provided by all other industries, including agriculture, manufacturing, transportation, utilities, communication, and construction. Uses of mined materials include coal for energy, copper for wiring, gold for satellites and sophisticated electronic components, and a variety of other minerals as ingredients in medicines and household products.

Mining is the process of digging into the earth to extract naturally occurring minerals. There are two kinds of mining, surface mining and underground mining. Surface mining, also called open-pit mining or strip mining, is undertaken if the mineral is near the earth surface. This method usually is more cost-effective and requires fewer workers to produce the same quantity of ore than does underground mining. In surface mining, after blasting with explosives, workers use huge earthmoving equipment, such as power shovels or draglines, to scoop off the layers of soil and rock covering the mineral bed. Once the mineral is exposed, smaller shovels are used to lift it from the ground and load it into trucks. The mineral also can be broken up using explosives, if necessary. In quarrying operations, workers use machines to extract stone used primarily as a building material. Stone, such as marble, granite, limestone, and sandstone, is quarried by splitting blocks of rock from a massive rock surface.

Underground mining is used when the mineral deposit lies deep below the surface of the earth. When developing an underground mine, miners first must dig two or more openings, or tunnels, deep into the earth near the place where they believe coal or minerals are located. Depending on where the vein of ore is in relation to the surface, tunnels may be vertical, horizontal, or sloping. One opening allows the miners to move in and out of the mine with their tools and also serves as a path for transporting the mined rock by small railroad cars or by conveyor belts to the surface. The other opening is used for ventilation.

Entries are constructed so that miners can get themselves and their equipment to the ore and carry it out, while allowing fresh air to enter the mine. Once dug to the proper depth, a mine tunnels interconnect with a network of passageways going in many directions. Long steel bolts and pillars of unmined ore support the roof of the tunnel. Using the room-and-pillar method, miners remove half of the ore as they work the ore seams from the tunnel entrance to the edge of the mine property, leaving columns of ore to support the ceiling. This process is then reversed, and the remainder of the ore is extracted, as the miners work their way back out. In the case of longwall mining of coal, self-advancing roof supports, made of hydraulic jacks and metal plates, are moved ahead, allowing the ceiling in the mined area to cave in as the miners work back towards the tunnel entrance.