Natural Resource Partners LP engages in the business of owning, managing, and leasing a diversified portfolio of mineral properties. It operates through the Coal Royalty and Other, and Soda Ash segments. The Coal Royalty and Other segment consists of coal royalty properties and coal-related transportation and processing assets. The Soda Ash segment consists of a non-controlling equity interest in a trona ore mining operation and soda ash refinery in the Green River Basin, Wyoming. The company was founded in April 2002 and is headquartered in Houston, TX.

NACCO Industries, Inc. is a holding company, which engages in the management of surface mines that supply coal to power generation companies. It operates through the following segments: Coal Mining, North American Mining (NAMining), and Minerals Management. The Coal Mining segment includes surface coal mines under long-term contracts with power generation companies and activated carbon producers. The NAMining segment offers value-added contract mining and other services for producers of aggregates, lithium, and other minerals. The Minerals Management segment focuses on the development of oil, gas, and coal reserves. The company was founded on February 18, 1986 and is headquartered in Cleveland, OH.

Alliance Resource Partners LP is a natural resource company, which produces and markets coal to United States utilities and industrial users. It operates through the following segments: Illinois Basin, Appalachia, Minerals, and Other & Corporate. The Illinois Basin segment is comprised of Webster County coal's Dotiki mining complex, Gibson mining complex, which includes the Gibson north mine and the Gibson south project, Hopkins County coal's Elk Creek mining complex, White County coal's Pattiki mining complex, Warrior's mining complex, River View's mining complex, the Sebree property and certain properties of Alliance Resource Properties and ARP Sebree LLC. The Appalachian segment is composed of Pontiki and MC Mining complexes. The Minerals segment includes its oil & gas mineral interests, which are located primarily in the Permian, Anadarko, and Williston basins. The Other and Corporate segment includes marketing and administrative expenses, Mt. Vernon dock activities, coal brokerage activity, its equity investment in Mid-America Carbonates LLC and certain activities of Alliance Resource Properties. The company was founded in 1971 and is headquartered in Tulsa, OK.

Peabody Energy Corp. engages in the business of coal mining. It operates through the following business segments: Seaborne Thermal, Seaborne Metallurgical, Powder River Basin, Other U.S. Thermal, and Corporate and Other. The Seaborne Thermal segment consist of mines in New South Wales, Australia. The Seaborne Metallurgical segment includes mines in Queensland, Australia, one in New South Wales, Australia and one in Alabama, USA. The Powder River Basin segment focuses on mines in Wyoming. The Other U.S. Thermal segment reflects on the mining, preparation and sale of thermal coal, sold primarily to electric utilities in the U.S. under long-term contracts, with a relatively small portion sold as international exports as conditions warrant. The Corporate and Other segment involves administrative expenses, results from equity method investments, trading and brokerage activities, minimum charges on certain transportation-related contracts, the closure of inactive mining sites, the impact of foreign currency remeasurement and certain commercial matters. The company was founded by Francis S. Peabody in 1883 and is headquartered in St. Louis, MO.