Williams Partners L.P. operates as an energy infrastructure company. It operates through Northeast G&P, Atlantic-Gulf, and West segments. The Northeast G&P segment engages in natural gas gathering, compression, processing, and NGL fractionation businesses in the Marcellus and Utica shale regions in Pennsylvania, West Virginia, New York, and Ohio. The Atlantic-Gulf segment operates Transco interstate natural gas pipeline that extends from the Gulf of Mexico to the eastern seaboard; and natural gas gathering, processing and treating, crude oil production handling, and NGL fractionation assets within the onshore, offshore shelf, and deep-water areas in and around the Gulf Coast states of Texas, Louisiana, Mississippi, and Alabama. This segment also operates various petrochemical and feedstock pipelines in the Gulf Coast region. The West segment operates Northwest Pipeline, an interstate natural gas pipeline, as well as natural gas gathering, processing, and treating assets in Colorado, New Mexico, Wyoming, Louisiana, Texas, Arkansas, and Oklahoma. This segment also operates NGL and natural gas marketing business, and storage facilities. The company owns and operates 33,000 miles of pipelines system providing natural gas for clean-power generation, heating, and industrial use. WPZ GP LLC serves as the general partner of the company. The company was founded in 2005 and is based in Tulsa, Oklahoma. Williams Partners L.P. is a subsidiary of Williams Gas Pipeline Company, LLC.