Lake Oahe 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 Dakota in the United States. The lake has an area of and a maximum depth of . By volume, it is the fourth-largest reservoir in the US. Lake Oahe has a length of approximately and has a shoreline of . 51 recreation areas are located along Lake Oahe, and 1.5 million people visit the reservoir every year. The lake is named for the 1874 Oahe Indian Mission. Lake Oahe begins just north of
Potrerillos Dam Potrerillos Dam Potrerillos Dam is located on the Mendoza River, in Argentina's Potrerillos Valley. The dam was built between 1999 and 2003 by a consortium consisting of Industrias Metalúrgicas Pescarmona (IMPSA) and Cartellone to provide flood control, hydroelectricity and irrigation water. The dam cost US$ 312 million to construct. Located about southwest of Mendoza, the concrete-faced rockfill dam is high and long, impounding the long Potrerillos Reservoir. The dam and reservoir have lost significant storage capacity due to the high silt content of the Mendoza River. When the reservoir was first filled in 2003, the capacity was estimated at ,