The Keystone Pipeline System is an oil pipeline system in Canada and the United States, commissioned in 2010 by TC Energy. It is owned by South Bow, since TC Energy's spin off of its liquids business into a separate publicly-traded company, effective October 1, 2024. It runs from the Western Canadian Sedimentary Basin in Alberta to refineries in Illinois and Texas, and also to oil tank farms and an oil pipeline distribution center in Cushing, Oklahoma.
TransCanada Keystone Pipeline GP Ltd, abbreviated here as Keystone, operates four phases of the project. In 2013, the first two phases had the capacity to deliver up to 590,000 barrels (94,000 m3) per day of oil into the Midwest refineries. Phase III has capacity to deliver up to 700,000 barrels (110,000 m3) per day to the Texas refineries. By comparison, production of petroleum in the United States averaged 9.4 million barrels (1.5 million cubic meters) per day in first-half 2015, with gross exports of 500,000 barrels (79,000 m3) per day through July 2015.
A proposed fourth pipeline, called Keystone XL (sometimes abbreviated KXL, with XL standing for "export limited") Pipeline, would have connected the Phase I-pipeline terminals in Hardisty, Alberta, and Steele City, Nebraska, by a shorter route and a larger-diameter pipe. It would have run through Baker, Montana, where American-produced light crude oil from the Williston Basin (Bakken formation) of Montana and North Dakota would have been added to the Keystone's throughput of synthetic crude oil (syncrude) and diluted bitumen (dilbit) from the oil sands of Canada. It is unclear how much of the oil transported through the pipeline would have reached American consumers instead of being exported to other countries, as most of it would have been refined along the Gulf Coast.
The pipeline became well known when the proposed KXL extension attracted opposition from environmentalists with concerns about climate change and fossil fuels. In 2015, KXL was temporarily delayed by President Barack Obama. On January 24, 2017, President Donald Trump took action intended to permit the pipeline's completion. On January 20, 2021, President Joe Biden signed an executive order to revoke the permit that was granted to TC Energy Corporation for the Keystone XL Pipeline (Phase 4). On June 9, 2021, TC Energy abandoned plans for the Keystone XL Pipeline.