NiSource Inc., an energy holding company, operates as a regulated natural gas and electric utility company in the United States. It operates in two segments, Gas Distribution Operations and Electric Operations. The company distributes natural gas to approximately 3.3 million customers through approximately 55,000 miles of distribution main pipeline and the associated individual customer service lines; and 1,000 miles of transmission main pipeline in northern Indiana, Ohio, Pennsylvania, Virginia, Kentucky, and Maryland. It also generates, transmits, and distributes electricity to approximately 0.5 million customers in various counties in the northern part of Indiana, as well as engages in wholesale electric and transmission transactions. It owns and operates coal-fired electric generating stations in Wheatfield and Michigan City; combined cycle gas turbine in West Terre Haute; natural gas generating units in Wheatfield; hydro generating plants in Carroll County and White County; wind generating units in White County, Indiana; and solar generating units in Jasper County and White County. The company was formerly known as NIPSCO Industries, Inc. and changed its name to NiSource Inc. in April 1999. NiSource Inc. was founded in 1847 and is headquartered in Merrillville, Indiana.

Alliance Resource Partners, L.P., a diversified natural resource company, produces and markets coal primarily to utilities and industrial users in the United States. The company operates through four segments: Illinois Basin Coal Operations, Appalachia Coal Operations, Oil & Gas Royalties, and Coal Royalties. It produces a range of thermal and metallurgical coal with sulfur and heat contents. The company operates seven underground mining complexes in Illinois, Indiana, Kentucky, Maryland, Pennsylvania, and West Virginia. In addition, it owns and leases oil and gas mineral interests and equity interests; and leases its coal mineral reserves and resources to its mining complexes; and leases land and operates a coal loading terminal on the Ohio River at Mt. Vernon, Indiana. Further, the company offers various mining technology products and services, including data network, communication and tracking systems, mining proximity detection systems, industrial collision avoidance systems, and data and analytics software. It also exports its products. The company was founded in 1971 and is headquartered in Tulsa, Oklahoma.

CONSOL Energy Inc., together with its subsidiaries, produces and sells bituminous coal in the United States and internationally. It operates through two segments, Pennsylvania Mining Complex (PAMC) and CONSOL Marine Terminal. The company's PAMC segment engages in the mining, preparing, and marketing of bituminous coal to power generators, industrial end-users, and metallurgical end-users. This segment includes the Bailey Mine, the Enlow Fork Mine, the Harvey Mine, and the central preparation plant. Its CONSOL Marine Terminal segment provides coal export terminal services through the Port of Baltimore. The company also develops and operates the Itmann Mining Complex located in Wyoming County, West Virginia; and Greenfield Reserves and Resources located in the Northern Appalachian, Central Appalachian, and Illinois basins. CONSOL Energy Inc. was founded in 1864 and is headquartered in Canonsburg, Pennsylvania.

Northern Oil and Gas, Inc., an independent energy company, engages in the acquisition, exploration, exploitation, development, and production of crude oil and natural gas properties in the United States. It primarily holds interests in the Williston Basin, the Appalachian Basin, and the Permian Basin in the United States. The company is based in Minnetonka, Minnesota.

Arch Resources, Inc. engages in the production and sale of metallurgical products. It operates in two segments, Metallurgical and Thermal. The company operates active mines. It owned or controlled primarily through long-term leases of coal land in Ohio, Maryland, Virginia, West Virginia, Wyoming, Kentucky, Montana, Pennsylvania, Colorado, and Illinois; and smaller parcels of property in Alabama, Indiana, Washington, Arkansas, California, Utah, and Texas. The company sells its products to utility, industrial, and steel producers in the United States and internationally. Arch Resources, Inc. was incorporated in 1969 and is headquartered in Saint Louis, Missouri.

Peabody Energy Corporation engages in coal mining business in the United States, Japan, Taiwan, Australia, India, Brazil, Belgium, Chile, France, Indonesia, China, Vietnam, South Korea, Germany, and internationally. The company operates through Seaborne Thermal, Seaborne Metallurgical, Powder River Basin, Other U.S. Thermal, and Corporate and Other segments. It is involved in the mining, preparation, and sale of thermal coal primarily to electric utilities; mining bituminous and sub-bituminous coal deposits; low sulfur and high British thermal unit thermal coal; and mining metallurgical coal, such as hard coking coal, semi-hard coking coal, semi-soft coking coal, and pulverized coal injection coal. The company supplies coal primarily to electricity generators, industrial facilities, and steel manufacturers. It also engages in marketing and brokering of coal from other coal producers; trading of coal and freight-related contracts, as well as provides transportation-related services. The company was founded in 1883 and is headquartered in Saint Louis, Missouri.

Natural Resource Partners L.P., together with its subsidiaries, owns, manages, and leases a portfolio of mineral properties in the United States. It operates in two segments, Mineral Rights and Soda Ash. The company owns interests in coal, soda ash, trona, and other natural resources. Its coal reserves are primarily located in the Appalachia Basin, the Illinois Basin, and the Northern Powder River Basin in the United States; industrial minerals and aggregates properties located in the United States; and oil and gas properties located in Louisiana. The company leases a portion of its reserves in exchange for royalty payments; and owns and leases transportation and processing infrastructure related to coal properties. NRP (GP) LP serves as the general partner of the company. Natural Resource Partners L.P. was incorporated in 2002 and is headquartered in Houston, Texas.

North American Construction Group Ltd. provides mining and heavy civil construction services to customers in the resource development and industrial construction sectors in Australia, Canada, and the United States. The company operates Heavy Equipment - Canada, Heavy Equipment - Australia, and Other segments. It also offers mine management services for thermal coal mines; and construction and operations support services in the Canadian oil sands region. In addition, the company provides fully maintained heavy equipment rentals and full service mine operations support at metallurgical and thermal coal mines; heavy equipment rentals to iron ore, gold and lithium producers; and heavy equipment maintenance, component remanufacturing, and full equipment rebuild services to mining companies and other heavy equipment operators, as well as supplies production-critical components to the mining and construction industry. As of December 31, 2023, it operated a heavy equipment fleet of 900 units. The company was formerly known as North American Energy Partners Inc. and changed its name to North American Construction Group Ltd. in April 2018. North American Construction Group Ltd. was incorporated in 1953 and is headquartered in Acheson, Canada.