Dallas-based Energy Transfer Partners made the announcement in a brief court filing with an appeals court in Washington, D.C. The announcement marks a significant development in the long battle over the project that will move North Dakota oil 2000 miles (1930 kilometers) through South Dakota and Iowa to a shipping point in Illinois. The pipeline is three months behind schedule due to large protests and the objections of two American Indian tribes who say it threatens their water supply and cultural sites. The tribes argue that a rupture in the section that crosses under Lake Oahe would threaten their water supply and sacred sites and would prevent them from practicing their religion, which requires clean water. [...] the Army Corps of Engineers, which manages the Missouri River for the government, rescinded the study and gave the company permission to complete the pipeline at the urging of President Donald Trump shortly after he took office.