An environmental advocacy group said it has lost several battles in its fight against the expansion of tar sands oil pipelines in Minnesota. Canadian pipeline company TransCanada aims to build Keystone XL to carry oil from tar sands projects in Alberta province. Rival company Enbridge has plans for major expansions to its existing Lakehead pipeline system to carry Canadian crude oil to U.S. Midwest market. The town of Clearbrook, Minn., serves as a pipeline hub for about 14 percent of the oil used in the United States. Enbridge directors said Clearbrook is \"increasingly busy\" and requires expansions to handle the expected glut of crude deliveries from Canada. Kevin Reuther, legal director for the Minnesota Center for Environmental Advocacy, told The Star Tribune newspaper in Minneapolis that groups like his have \"pretty much lost every battle\" against tar sands in Minnesota. Line 14, part of the Lakehead oil pipeline system operated by Enbridge, ruptured in late July, releasing around 1,200 barrels of oil near Grand Marsh, Wis. A 2010 spill from the same network in Michigan was the costliest onshore incident in U.S. history.