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 Transco and Northwest natural gas pipelines; and natural gas gathering and processing, and crude oil production handling and transportation assets in the Gulf Coast region, as well as various petrochemical and feedstock pipelines.