OGE Energy Corp., together with its subsidiaries, operates as an energy and energy services provider that offers physical delivery and related services for electricity and natural gas primarily in the south-central United States. It operates in two segments, Electric Utility and Natural Gas Midstream Operations. The Electric Utility segment generates, transmits, distributes, and sells electric energy. This segment furnishes retail electric service in 267 communities and their contiguous rural and suburban areas and owns and operates coal-fired, natural gas-fired, wind-powered, and solar-powered generating assets. Its service area covers 30,000 square miles in Oklahoma and western Arkansas, including Oklahoma City in Oklahoma and Fort Smith, Arkansas. The Natural Gas Midstream Operations segment engages in gathering, processing, transporting, and storing natural gas and the provision of crude oil gathering services, and interstate and intrastate natural gas pipeline transportation and storage services primarily to its producer, power plant, local distribution company, and industrial end-user customers. As of December 31, 2020, the company owned and operated interconnected electric generation, transmission, and distribution systems, including 15 generating stations with an aggregate capability of 7,120 megawatts and transmission systems comprising 402 substations and 5,122 structure miles of lines in Oklahoma, and 36 substations and 277 structure miles of lines in Arkansas. Its distribution systems included 349 substations 29,443 structure miles of overhead lines 3,202 miles of underground conduit and 11,038 miles of underground conductors in Oklahoma, as well as 29 substations, 2,788 structure miles of overhead lines, 338 miles of underground conduit, and 669 miles of underground conductors in Arkansas. The company was founded in 1902 and is headquartered in Oklahoma City, Oklahoma.