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
Parker Dam Parker Dam Parker Dam is a concrete arch-gravity dam that crosses the Colorado River downstream of Hoover Dam. Built between 1934 and 1938 by the Bureau of Reclamation, it is high, of which are below the riverbed, making it the deepest dam in the world. The dam's primary functions are to create a reservoir, and to generate hydroelectric power. The reservoir behind the dam is called Lake Havasu and can store or over 210 billion US gallons. The dam straddles the state border at the narrows the river passes through between the Whipple Mountains of California and the Buckskin Mountains