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
Westville Dam Westville Dam The Westville Dam is located on the Quinebaug River between Southbridge and Sturbridge, about west of the Southbridge town center and southwest of Worcester, Massachusetts. Designed and constructed by the United States Army Corps of Engineers, this dam substantially reduces flooding along the Quinebaug and Thames rivers. Construction of the project began in June 1960 with completion in August 1962 at a cost of US$5.6 million. The Westville reservoir is located within the Quinebaug River Watershed and is part of the Thames River Basin. Access to the site is available from Interstate 84 and State Route 131. The