President Trump, flanked by Commerce Secretary Wilbur Ross (left) and Energy Secretary Rick Perry (right), announces the approval of a permit to build the Keystone XL pipeline, in March 2017. Evan Vucci/AP hide caption
Keystone XL Pipeline Keystone XL Pipeline
A wooden cross marks an unidentified U.S. Army grave at Fort Laramie, Wyo., as pictured in 2009. The Fort Laramie National Historic Site will host a gathering of Lakota people this weekend to commemorate an 1868 treaty with the U.S. government. Matt Joyce/AP hide caption
Amid Keystone XL Fight, The Lakota Treaty Of Fort Laramie Turns 150
Miles of unused pipe, prepared for the proposed Keystone XL pipeline, sit in a lot outside Gascoyne, N.D., in 2014. Andrew Burton/Getty Images hide caption
A protest sign sits in the proposed path of the Keystone XL Pipeline in Silver Creek, Neb. Nati Harnik/AP hide caption
Russ Girling, president and CEO of TransCanada Corporation, addresses the company's annual meeting in 2015 in Calgary, Alberta. Jeff McIntosh/The Canadian Press hide caption
President Trump points toward members of the media while seated at his desk on Air Force One Thursday. Pablo Martinez Monsivais/AP hide caption
President Trump, accompanied by Vice President Pence and staff, signed multiple documents regarding two major oil pipelines in the U.S. Evan Vucci/AP hide caption
Demonstrators chant and hold up signs as they gather in front of the White House in Washington, D.C., to protest the Dakota Access Pipeline in September. Jim Watson/AFP/Getty Images hide caption
President Obama, flanked by Secretary of State John Kerry (right) and Vice President Joe Biden, announced the Keystone XL pipeline decision Friday in the Roosevelt Room of the White House. Mandel Ngan/AFP/Getty Images hide caption
Miller Farm, the terminus of Van Syckel's pipeline, in 1868. The oil was pumped to Miller Farm and then transported by railroad. Drake Well Museum/Courtesy of PHMC hide caption
House Energy and Commerce Committee Chairman Fred Upton, R-Mich., left, clasps hands with Sen. John Hoeven, R-N.D., sponsor of the Senate's Keystone XL pipeline bill version, on Wednesday as lawmakers gather to urge President Obama to sign the legislation approving expansion of the Keystone XL pipeline. The House passed the Senate's version of the bill Wednesday afternoon. J. Scott Applewhite/AP hide caption
A placard with the Canadian flag rests on the ground covered in oil as demonstrators protest against the Keystone XL Pipeline and the Alberta tar sands. Nam Y. Huh/AP hide caption
Senate Majority Leader Mitch McConnell, R-Ky., prepares to speak to the media Thursday before the Senate voted to approve the Keystone XL pipeline. Jim Lo Scalzo /EPA /Landov hide caption
An excavator loads a truck with oil sands at the Suncor mine near the town of Fort McMurray in Alberta, Canada in 2009. Environmental groups that oppose oil sands mining have pointed to delayed and canceled projects as a sign of recent success. Mark Ralston/AFP/Getty Images hide caption
Susan and Bill Dunavan own 80 acres of land in York County. Melissa Block/NPR hide caption
Pipes for Transcanada Corp.'s planned Keystone XL oil pipeline are stacked at a depot in Gascoyne, N.D. The House of Representatives approved the Keystone XL pipeline Friday; the Senate voted against it on Tuesday. Andrew Cullen/Reuters/Landov hide caption
GOP Rep. Bill Cassidy and Democratic Sen. Mary Landrieu face off in a Dec. 6 Senate runoff. Both are pushing for legislation approving the remaining leg of the Keystone XL pipeline between Alberta, Canada, and Steele City, Neb. Gerald Herbert/AP hide caption
Pipes for TransCanada's planned Keystone XL pipeline are stored in Gascoyne, N.D. The U.S. House has voted to approve the proposed project, which would allow crude oil to flow from Canada to the Gulf of Mexico. The Senate plans to vote Tuesday on legislation that would greenlight the project. Andrew Cullen/Reuters/Landov hide caption
U.S. Rep. Juan Vargas, D-Calif., speaks Wednesday as U.S. military veterans, service members and immigration reform advocates look on during a press conference urging President Obama to move forward with immigration reform at the U.S. Capitol in Washington. Saul Loeb/AFP/Getty Images hide caption
Sen. Mary Landrieu, D-La., chair of the Senate energy committee, spoke Wednesday about getting congressional approval for the Canada-to-Texas Keystone XL pipeline. With her is Sen. Joe Manchin, D-W.Va., a member of the committee. J. Scott Applewhite/AP hide caption