Lake Oahe "a memorandum and an executive order asking USACE to expedite its consideration of the company’s application for an easement to start construction." The USACE subsequently "withdrew its call for the environmental study." On 7 February 2017, the USACE approved an easement through Lake Oahe. On 9 February 2017, the Cheyenne River Sioux filed the first legal challenge to the easement, citing an 1851 treaty and interference with the religious practices of the tribe. Lake Oahe Lake Oahe (oh-WAH'-hee) is a large reservoir behind Oahe Dam on the Missouri River; it begins in central South Dakota and continues north into North
Lake Oahe Rock Indian Reservation brought a petition to the U.S. Army Corps of Engineers (USACE) and sued for an injunction to stop the project. On December 4, 2016 USACE denied the easement that "would allow the Dakota Access Pipeline to cross under Lake Oahe" and Jo-Ellen Darcy, the United States Assistant Secretary of the Army "said she based her decision on a need to explore alternate routes for the Dakota Access Pipeline crossing." Darcy said "that the consideration of alternative routes would be best accomplished through an Environmental Impact Statement with full public input and analysis." President Trump soon thereafter issued