Alliance Resource Partners is a natural resource company. The company is a coal producer in the eastern United States. The company markets its coal production to main domestic and international utilities and industrial users. The company has two reportable segments: Illinois Basin, which comprises of multiple operating segments, including operating mining complexes Webster County Coal's Dotiki mining complex, Gibson County Coal's mining complex, River View's mining complex and the Hamilton mining complex; and Appalachia, which comprises of multiple operating segments, including the Mettiki mining complex, the Tunnel Ridge mining complex, the MC Mining mining complex and the Penn Ridge property.

Contura Energy is a coal supplier with affiliate mining operations across major coal basins in Pennsylvania, Virginia and West Virginia. The company's portfolio of mining operations consists of underground mines, surface mines and coal preparation plants. In the Central Appalachia (CAAP) coal basin, the company mainly produces low-ash metallurgical coal, which are shipped to domestic and international coke and steel producers. In the CAPP coal basin, the company also produces low sulfur, high British thermal unit (BTU) thermal coal for electricity generation, as well as specialty coal for industrial customers. In the Northern Appalachia coal basin, the company produces primarily high-BTU thermal coal.

Arch Coal is a coal producer. The company's main business is the production of thermal and metallurgical coal from surface and underground mines located throughout the United Staets, for sale to utility, industrial and steel producers both in the United States and around the world. The company's segments are based on two lines of business, metallurgical coal and thermal coal, and may include a number of mine complexes. The company's segments are: the Powder River Basin, containing primary thermal operations in Wyoming; the Metallurgical, containing metallurgical operations in West Virginia; and the Other Thermal, containing supplementary thermal operations in Colorado and Illinois.

CNX Resources is an independent oil and gas company focused on the exploration, development, production, gathering, processing and acquisition of natural gas properties primarily in the Appalachian Basin. The company's operations are centered on unconventional shale formations, primarily the Marcellus Shale and Utica Shale. The company operates, develops and explores for natural gas in Appalachia (Pennsylvania, West Virginia, Ohio, and Virginia).

CONSOL Energy is a producer of bituminous coal, focused on the extraction and preparation of coal in the Appalachian Basin. The company's primary businesses consist of its: Pennsylvania Mining Complex; CONSOL Coal Resources LP (CCR or Partnership) Ownership, in which the company owns directly or indirectly, through CCR's general partner, an interest in the partnership; CONSOL Marine Terminal, in which through its subsidiary, CONSOL Marine Terminals LLC, the company provides coal export terminal services through the Port of Baltimore; and Greenfield Reserves, in which the company has ownership of undeveloped coal reserves located in the Northern Appalachian Basin, the Central Appalachian Basin, and the Illinois Basin.

Hallador Energy is engaged in the production of steam coal from mines located in western Indiana. The company also owns a 50% interest in Sunrise Energy, LLC, a private gas exploration company with operations in Indiana. Additionally, the company owns 100% of Hourglass Sands, LLC, a frac sand mining company in the State of Colorado.

Natural Resource Partners owns, manages and leases a portfolio of mineral properties, including interests in coal, soda ash from trona and other natural resources. The company has two segments: coal royalty and other, which consists primarily of coal royalty properties and coal related transportation and processing assets; and soda ash, which, via Ciner Resources LP, the company's operating partner, mines trona, processes it into soda ash, and distributes the soda ash both domestically and internationally into the glass and chemicals industries. The company's operations are conducted through its NRP (Operating) LLC susbsidiary, and its operating assets are owned by its subsidiaries.

Peabody Energy is a coal company, engaged in the mining of thermal coal for sale primarily to electric utilities and metallurgical coal for sale to industrial customers. The company owns interests in several coal mining operations located in the U.S. and Australia. The company has a majority interest in several of those mining operations and an equity interest in Middlemount Coal Pty Ltd. (Middlemount), which owns the Middlemount Mine in Queensland, Australia. In addition to its mining operations, the company markets and brokers coal from other coal producers, both as principal and agent, and trade coal and freight-related contracts through trading and business offices in the U.S., Australia, China, and the U.K.