The Keystone Pipeline System is an oil pipeline system in Canada and the United States, commissioned in 2010 and now owned solely by TransCanada Corporation.[1] 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.[2] The pipeline became well-known when a planned fourth phase, Keystone XL, attracted opposition from environmentalists, becoming a symbol of the battle over climate change and fossil fuels.  In 2015 Keystone XL was temporarily delayed by then–President Barack Obama. On January 24, 2017, President Donald Trump took action intended to permit the pipeline's completion.