[4] During the spring and fall of 1907, the company built a gas pipeline from Osage County to Sapulpa and Oklahoma City.

[9][10] In October 2002, Oneok acquired the Texas division and assets of Southern Union Gas for $420 million.

[13][14] In November 2021, Oneok resumed construction of its natural gas processing facility Demicks Lake III plant in McKenzie County, North Dakota which was originally delayed due to the COVID-19 pandemic.

[16] In July 2022, a Oneok gas plant in Medford, Oklahoma exploded, causing no injuries but temporarily expelling roughly 1,000 residents from their homes.

[17] In January 2023, Oneok reached an insurance settlement payment of $930 million and the company announced plans to transition gas fractionation operations away from the Medford plant.

[20] In May 2024, Oneok agreed to acquire Gulf Coast NGL Pipelines from Easton Energy for $280 million.

[27] Magellan Midstream Partners operates as a subsidiary of Oneok and owns approximately 2,200 miles of crude pipelines, and the 450-mile Longhorn pipeline, which transports roughly 275,000 barrels per day of crude oil from the Permian Basin to storage and refining facilities in Houston.