The Williams Companies, Inc., together with its subsidiaries, operates as an energy infrastructure company primarily in the United States. It operates through Transmission & Gulf of Mexico, Northeast G&P, West, and Gas & NGL Marketing Services segments. The Transmission & Gulf of Mexico segment comprises natural gas pipelines; Transco, Northwest pipeline, MountainWest, and related natural gas storage facilities; and natural gas gathering and processing, and crude oil production handling and transportation assets in the Gulf Coast region. The Northeast G&P segment engages in the midstream gathering, processing, and fractionation activities in the Marcellus Shale region primarily in Pennsylvania and New York, and the Utica Shale region of eastern Ohio. The West segment consists of gas gathering, processing, and treating operations in the Rocky Mountain region of Colorado and Wyoming, the Barnett Shale region of north-central Texas, the Eagle Ford Shale region of South Texas, the Haynesville Shale region of northwest Louisiana, the Mid-Continent region that includes the Anadarko and Permian basins, and the DJ Basin of Colorado; and operates natural gas liquid (NGL) fractionation and storage facilities in central Kansas near Conway. The Gas & NGL Marketing Services segment provides wholesale marketing, trading, storage, and transportation of natural gas for natural gas utilities, municipalities, power generators, and producers; asset management services; and transports and markets NGLs. The company owns and operates 33,000 miles of pipelines. The Williams Companies, Inc. was founded in 1908 and is headquartered in Tulsa, Oklahoma.

Energy Transfer LP provides energy-related services. The company owns and operates natural gas transportation pipeline, and natural gas storage facilities in Texas and Oklahoma; and approximately 20,090 miles of interstate natural gas pipeline. It also sells natural gas to electric utilities, independent power plants, local distribution and other marketing companies, and industrial end-users. In addition, the company owns and operates natural gas gathering pipelines, processing plant, and treating and conditioning facilities in Texas, New Mexico, West Virginia, Pennsylvania, Ohio, Oklahoma, Arkansas, Kansas, Montana, North Dakota, Wyoming, and Louisiana; natural gas gathering, oil pipeline, and oil stabilization facilities in South Texas; and transports and supplies water to natural gas producer in Pennsylvania. Further, it owns 5,700 miles of natural gas liquid (NGL) pipeline; NGL fractionation facilities; NGL storage facilities; and other NGL storage assets and terminal. Additionally, the company provides crude oil transportation, terminalling, acquisition, and marketing activities; owns and operates approximately 14,500 miles of crude oil trunk and gathering pipelines in the Southwest, Midcontinent, and Midwest United States; and sells and distributes gasoline, middle distillate, and motor fuels and other petroleum products. It also offers natural gas compression services; carbon dioxide and hydrogen sulfide removal services; and manages coal and natural resources properties, as well as sells standing timber, leases coal-related infrastructure facilities, collects oil and gas royalty, and generate electrical power. The company was formerly known as Energy Transfer Equity, L.P. and changed its name to Energy Transfer LP in October 2018. Energy Transfer LP was founded in 1996 and is headquartered in Dallas, Texas.

ONEOK, Inc. engages in gathering, processing, fractionation, storage, transportation, and marketing of natural gas and natural gas liquids (NGL) in the United States. It operates through four segments: Natural Gas Gathering and Processing, Natural Gas Liquids, Natural Gas Pipelines, and Refined Products and Crude. The company owns natural gas gathering pipelines and processing plants in the Mid-Continent and Rocky Mountain regions; and provides midstream services to producers of NGLs. It also owns NGL gathering and distribution pipelines in Oklahoma, Kansas, Texas, New Mexico, Montana, North Dakota, Wyoming, and Colorado; terminal and storage facilities in Kansas, Nebraska, Iowa, and Illinois; NGL distribution pipelines in Kansas, Nebraska, Iowa, Illinois, and Indiana; transports refined petroleum products, including unleaded gasoline and diesel; and owns and operates truck- and rail-loading, and -unloading facilities connected to NGL fractionation, storage, and pipeline assets. In addition, the company transports and stores natural gas through regulated interstate and intrastate natural gas transmission pipelines, and natural gas storage facilities. Further, it owns and operates a parking garage in downtown Tulsa, Oklahoma; and leases excess office space and rail cars. Additionally, the company transports, stores, and distributes refined products, NGLs, and crude oil, as well as conducts commodity-related activities, including liquids blending and marketing activities. It serves integrated and independent exploration and production companies; other NGL and natural gas gathering and processing companies; crude oil and natural gas production companies; utilities; industrial companies; natural gasoline distributors; propane distributors; municipalities; ethanol producers; petrochemical, refining, and marketing companies; and heating fuel users, refineries, and exporters. ONEOK, Inc. was founded in 1906 and is headquartered in Tulsa, Oklahoma.

DTE Energy Company engages in the utility operations. The company's Electric segment generates, purchases, distributes, and sells electricity to various residential, commercial, and industrial customers in southeastern Michigan. It generates electricity through coal-fired plants, hydroelectric pumped storage, and nuclear plants, as well as wind and solar assets. This segment owns and operates distribution substations and line transformers. The company's Gas segment purchases, stores, transports, distributes, and sells natural gas to various residential, commercial, and industrial customers throughout Michigan; and sells storage and transportation capacity. Its DTE Vantage segment offers metallurgical and petroleum coke to steel and other industries; and power generation, steam production, chilled water production, and wastewater treatment services, as well as air supplies compressed air to industrial customers. Its Energy Trading segment engages in power, natural gas, and environmental marketing and trading; structured transactions; and the optimization of contracted natural gas pipeline transportation and storage positions. The company was founded in 1849 and is based in Detroit, Michigan.

Atmos Energy Corporation, together with its subsidiaries, engages in the regulated natural gas distribution, and pipeline and storage businesses in the United States. It operates through two segments, Distribution, and Pipeline and Storage. The Distribution segment is involved in the regulated natural gas distribution and related sales operations in eight states. This segment distributes natural gas to approximately 3.3 million residential, commercial, public authority, and industrial customers; and owned 73,689 miles of underground distribution and transmission mains. The Pipeline and Storage segment engages in the pipeline and storage operations. This segment transports natural gas for third parties and manages five underground storage facilities in Texas; provides ancillary services customary to the pipeline industry, including parking arrangements, lending, and inventory sales; and owned 5,645 miles of gas transmission lines. Atmos Energy Corporation was founded in 1906 and is headquartered in Dallas, Texas.

CMS Energy Corporation operates as an energy company primarily in Michigan. The company operates through three segments: Electric Utility; Gas Utility; and Enterprises. The Electric Utility segment is involved in the generation, purchase, transmission, distribution, and sale of electricity. This segment generates electricity through coal, wind, gas, renewable energy, oil, and nuclear sources. Its distribution system comprises 208 miles of high-voltage distribution overhead lines; 4 miles of high-voltage distribution underground lines; 4,428 miles of high-voltage distribution overhead lines; 19 miles of high-voltage distribution underground lines; 82,474 miles of electric distribution overhead lines; 9,395 miles of underground distribution lines; 1,093 substations; and 3 battery facilities. The Gas Utility segment engages in the purchase, transmission, storage, distribution, and sale of natural gas, which includes 2,392 miles of transmission lines; 15 gas storage fields; 28,065 miles of distribution mains; and 8 compressor stations. The Enterprises segment is involved in the independent power production and marketing, including the development and operation of renewable generation. It serves 1.9 million electric and 1.8 million gas customers, including residential, commercial, and diversified industrial customers. The company was incorporated in 1987 and is headquartered in Jackson, Michigan.

Plains All American Pipeline, L.P., through its subsidiaries, engages in the pipeline transportation, terminaling, storage, and gathering of crude oil and natural gas liquids (NGL) in the United States and Canada. The company operates through two segments, Crude Oil and NGL. The Crude Oil segment offers gathering and transporting crude oil through pipelines, gathering systems, trucks, and on barges or railcars. This segment provides terminaling, storage, and other facilities-related services, as well as merchant activities. The NGL segment is involved in natural gas processing and NGL fractionation, storage, transportation, and terminaling. This segment also includes ethane, propane, normal butane, iso-butane, and natural gasoline derived from natural gas production and processing activities, as well as crude oil refining processes. Its NGL components are used for various applications, such as heating, engine, and industrial fuels. The company was founded in 1981 and is headquartered in Houston, Texas. Plains All American Pipeline, L.P. operates as a subsidiary of Plains GP Holdings, L.P.

EnLink Midstream, LLC provides midstream energy services in the United States. The company operates through Permian, Louisiana, Oklahoma, North Texas, and Corporate segments. It is involved in gathering, compressing, treating, processing, transporting, storing, and selling natural gas; fractionating, transporting, storing, and selling natural gas liquids; and gathering, transporting, stabilizing, storing, trans-loading, and selling crude oil and condensate, as well as providing brine disposal services. In addition, the company's midstream energy asset network includes natural gas processing plants; fractionators; barge and rail terminals; product storage facilities; and brine disposal wells. EnLink Midstream, LLC was incorporated in 2013 and is based in Dallas, Texas.