ONEOK Partners, L.P. engages in the gathering, processing, storage, and transportation of natural gas in the United States. It operates through three segments: Natural Gas Gathering and Processing, Natural Gas Liquids, and Natural Gas Pipelines. The Natural Gas Gathering and Processing segment gathers and processes natural gas produced from crude oil and natural gas wells located in the Mid-Continent region; and gathers and processes natural gas in the Williston Basin, which spans portions of Montana and North Dakota, and the Powder River Basin of Wyoming. The Natural Gas Liquids segment gathers, treats, fractionates, and transports natural gas liquids (NGLs), as well as stores, markets, and distributes NGL products primarily in Oklahoma, Kansas, Texas, New Mexico, and the Rocky Mountain region. This segment also owns the Federal Energy Regulatory Commission (FERC)-regulated NGLs gathering and distribution pipelines in Oklahoma, Kansas, Texas, New Mexico, Montana, North Dakota, Wyoming, and Colorado; terminal and storage facilities in Missouri, Nebraska, Iowa, and Illinois; and FERC-regulated NGLs distribution and refined petroleum product pipelines in Kansas, Missouri, Nebraska, Iowa, Illinois, and Indiana. The Natural Gas Pipelines segment owns and operates regulated natural gas transmission pipelines and natural gas storage facilities; and provides natural gas transportation and storage services. This segments interstate natural gas pipeline assets transport natural gas through FERC-regulated interstate natural gas pipelines in North Dakota, Minnesota, Wisconsin, Illinois, Indiana, Kentucky, Tennessee, Oklahoma, Texas, and New Mexico. It also transports intrastate natural gas through its assets in Oklahoma; and owns underground natural gas storage facilities in Oklahoma, Texas, and Kansas.